JP5381041B2 - Mold device for in-mold foam molding - Google Patents

Description

  The present invention relates to a mold apparatus for in-mold foam molding in which foamed resin particles are heated and foam-fused in a molding space to obtain a molded product.

  As molding technology for foamed molded products, foamable resin particles made of thermoplastic synthetic resin materials such as polystyrene, polypropylene and polyethylene are filled into the molding space, and this is heated, foamed and fused with steam, etc., and then cooled. An in-mold foam molding apparatus configured to obtain a foam molded article having a desired shape is widely known.

  A mold apparatus for the in-mold foam molding apparatus includes a concave unit having a concave mold and a concave housing that holds the concave mold, and a convex unit having a convex mold and a convex housing that holds the convex mold. Widely adopted. The concave housing includes a rectangular cylindrical concave frame provided so as to surround the concave mold, a concave fixing plate that closes the opening on the back side of the concave frame, an end on the front side of the concave mold, and a concave mold and a concave mold. A concave center plate that closes an opening formed between the frames and a concave chamber for supplying steam and cooling water is formed in the concave housing on the back side of the concave. In addition, the convex housing includes a rectangular cylindrical convex frame provided so as to surround the convex mold, a convex fixing plate that closes the opening on the back side of the convex frame, and an end on the convex rear side. A convex center plate for closing the opening formed between the convex mold and the convex frame, and for supplying steam and cooling water into the convex housing on the rear side of the convex mold Those having a convex chamber are widely used.

  The convex fixing plate or the concave fixing plate is provided with a filling device for filling the expandable resin particles, and the convex housing and the concave housing are for supplying steam to the convex chamber and the concave chamber. Steam pipes and cooling water pipes for supplying cooling water are respectively connected, and drain pipes are connected to the lower portions of both housings. When molding the molded product, the foamed resin particles filled in the molding space are heated by the steam supplied to the convex chamber or the concave chamber, and the cooling water sprayed on the back side of the convex chamber or the concave chamber is used. The molded product is cooled, but the heating and cooling at the time of molding is not only foamable resin particles, but also molds and housings, fillers and ejector pins, steam piping and cooling that do not require heating or cooling. Since water pipes are also used, there is a problem that a lot of energy is wasted.

  In view of this, various types of metal mold apparatuses have been proposed and put into practical use in order to save energy by heating only the molds locally instead of heating the entire mold, thereby reducing the amount of steam used. For example, a foam molding apparatus (see, for example, Patent Document 1) including an independent steam chamber for each mold or a plurality of molds out of a plurality of molding molds, or a core mold. Also, a foam molding apparatus (see, for example, Patent Document 2) in which an exterior member surrounding the back side opposite to the molding space of the cavity mold is provided and an independent steam chamber is formed for each of the core mold and the cavity mold. ing.

  On the other hand, a method of lining butyl rubber on the inner surface of the housing has been proposed and put into practical use in order to suppress heat transfer to the housing and reduce steam consumption. However, this method has problems such as deformation and peeling due to heat-resistant temperature and linear expansion of rubber, a decrease in heat insulation effect due to aging, and difficulty in repair. Therefore, as a heat insulating material to replace the rubber lining, a method of coating an epoxy resin on the inner surface of the housing (see, for example, Patent Document 3), a coating material is applied to the inner surface of the housing, a mold apparatus and a molding machine, There has been proposed a method (for example, see Patent Document 4) for applying to the connecting portion.

Japanese Utility Model Publication No.59-7072 JP 11-48349 A JP 2003-236872 A JP 2007-1277 A

  By the way, when the volume of the steam chamber is set to be small as in the conventional mold apparatus to save energy, for example, as in the invention described in Patent Document 1, the steam chamber on the back side of the convex shape is partitioned. It is necessary to provide a partition plate or to provide an exterior member surrounding the back side opposite to the molding space of the core mold and the cavity mold as in the invention described in Patent Document 2, Since it is difficult to apply and the number of parts constituting the mold apparatus increases, the manufacturing cost of the mold apparatus increases, and the heat capacity of the mold apparatus increases, and the energy consumption required for heating and cooling correspondingly increases. There was a problem of increasing.

  In addition, as in the inventions described in Patent Documents 3 and 4, when coating an epoxy resin or paint, a slight energy saving effect is recognized by delaying heat transfer to the housing, but the mold itself is different from the conventional one. Since it has the same structure and the heat capacity of the entire mold is the same, it did not lead to significant steam reduction. Moreover, although a highly durable coating material has been developed, there remains a problem that a decrease in the heat insulation effect due to aging cannot be avoided.

  The object of the present invention is to realize a significant energy saving by reducing the heat capacity of the mold apparatus, to improve the molding efficiency by increasing the response speed of heating and cooling, and to reduce the number of parts of the mold apparatus. Another object of the present invention is to provide a mold apparatus for in-mold foam molding that can reduce the manufacturing cost of the mold apparatus.

A mold apparatus for in-mold foam molding according to the present invention has a concave mold and a concave housing that holds the concave mold, a concave unit in which a concave chamber is formed in the concave housing on the back side of the concave mold, a convex mold and the concave mold unit. And a convex unit in which a convex chamber is formed in the convex housing on the back side of the convex mold, and the two units are combined to form a concave mold and a convex mold. A mold apparatus for in-mold foam molding in which foamable resin particles are filled in a space, and the foamable resin particles are heated and foam-fused in a molding space to obtain a molded product, wherein the concave mold is for the recessed housing and the front end of the concave type is supported by the shape has so piece a free end, a front opening that opens toward the convex unit side between the concave free end and recessed housing Forming a concave portion and While the combination of the mold, to close the front opening in the convex unit, in which the concave chambers without the airtight.

  In this mold apparatus, the concave mold is supported in a cantilever manner on the concave housing, and a front opening opening toward the convex unit side is formed between the concave mold and the concave housing, so at least the center plate of the concave unit Can be omitted. For this reason, the heat capacity of the mold apparatus can be reduced by the amount of omitting the center plate, energy saving during molding can be realized, the response speed of heating and cooling of the mold apparatus can be increased, and the molding efficiency can be improved. By reducing the number of parts of the mold apparatus, the manufacturing cost of the mold apparatus can be reduced. Further, since it is only necessary to omit the center plate of the concave housing, the present invention can be easily applied to an existing mold apparatus without making a significant design change. On the other hand, by omitting the center plate, the concave unit is formed with a front opening between the concave mold and the concave housing. The front opening closes the concave mold and the convex mold for molding. Since both molds are combined and closed by the convex mold unit, the foaming resin particles are filled into the molding space, foamed with steam, heat-sealed, and cooled in the same manner as conventional mold devices. The molded product can be molded by cooling with water.

  Here, the concave housing includes a concave frame provided so as to surround the concave mold, a concave fixing plate for closing the opening on the back side of the concave frame, and a fixing member for fixing the concave mold to the concave fixing plate in a cantilevered manner. And forming a front opening that opens toward the convex unit side between the concave mold and the concave frame. By configuring in this way, the center plate of the concave unit can be omitted without difficulty.

  The convex housing has a convex frame provided so as to surround the convex mold, and a convex fixing plate that closes an opening on the back side of the convex frame, and closes the convex rear opening. It is also a preferred embodiment that a convex mold is fixed to a convex fixing plate and a convex chamber is formed on the back side of the convex mold. In this case, since the center plates of both units can be omitted, the heat capacity of the mold apparatus can be reduced, further energy saving can be realized during molding, and the response speed of heating and cooling can be increased to further improve the molding efficiency. In addition, the number of parts of the mold apparatus can be reduced and the manufacturing cost of the mold apparatus can be reduced.

  The convex unit may be formed with a restricting portion that restricts the concave free end from bulging outward. As described above, in the present invention, since at least the center plate of the concave unit is omitted and the front side end of the concave is the free end, the free end is moved outward by the foaming pressure of the foamed resin particles during molding. Try to transform. Therefore, in the present invention, by providing the convex unit with a restricting portion that restricts the concave free end portion from bulging outward, the outer side of the free end portion can be obtained without complicating the mold structure. The deformation | transformation into can be controlled and the fall of the shaping | molding precision by a free end part spreading outside can be prevented.

  Cover substantially the entire inner surfaces of the convex housing and the concave housing with a heat insulating material having a thermal conductivity of 2.5 kcal / m · h · ° C. or less, or cover the entire outer surfaces of the convex housing and the concave housing. It is also preferable to coat with a heat insulating material having a thermal conductivity of 2.5 kcal / m · h · ° C. or less. In this case, by covering the inner and outer surfaces of the convex housing and the concave housing with a heat insulating material, heat is transferred to the convex housing and the concave housing, and heat is released from the convex housing and the concave housing to the outside. Therefore, it is possible to further reduce energy consumption of the in-mold foam molding die device by reducing wasteful consumption of heat energy.

  According to the mold apparatus for in-mold foam molding according to the present invention, the concave mold is supported by the concave housing in a cantilever manner, and a front opening that opens toward the convex unit side is formed between the concave mold and the concave housing. Therefore, at least the center plate of the concave unit can be omitted. For this reason, the heat capacity of the mold apparatus can be reduced by the amount of omitting the center plate, energy saving during molding can be realized, the response speed of heating and cooling of the mold apparatus can be increased, and the molding efficiency can be improved. By reducing the number of parts of the mold apparatus, the manufacturing cost of the mold apparatus can be reduced. Further, since it is only necessary to omit the center plate of the concave housing, the present invention can be easily applied to an existing mold apparatus without making a significant design change.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
As shown in FIGS. 1 and 2, an in-mold foam molding mold apparatus 1 includes a concave unit 10 having a concave mold 11 and a concave housing 12 that holds the concave mold 11, a convex mold 21, and a convex housing that holds the convex mold 21. And the unit 10 and 20 are combined to fill the molding space 2 formed by the concave mold 11 and the convex mold 21 with foamable resin particles. The foamed resin particles are heated and foam-fused to obtain a molded product.

  The concave mold 11 and the convex mold 21 are made of a material having a low specific heat and a high thermal conductivity, for example, a casting made of an aluminum alloy so that the molded product can be heated and cooled smoothly. In order to reduce the manufacturing cost of the mold apparatus 1 and to ensure sufficient strength and rigidity, the mold apparatus 1 is made of an iron-based metal.

  The concave housing 12 includes a rectangular tube-shaped concave frame 13 provided so as to surround the concave mold 11, a concave fixing plate 14 that closes an opening on the back side of the concave frame 13, and the concave mold 11 on the concave fixing plate 14 in a cantilever shape. A concave chamber 16 is formed in the concave housing 12 on the back side of the concave mold 11. The concave mold 11 is fixed and supported in a cantilever manner on the concave mold fixing plate 14 via the fixing member 15 with the opening side facing the front side (the mating surface side of the concave mold 11 and the convex mold 21). The part 11a is configured with a free end. That is, in the conventional mold apparatus 1, as shown by the phantom line in FIG. 2, the front side end portion 11 a of the concave mold 11 is fixed to the concave frame 13 via the center plate 30. In the device 1, the center plate 30 is omitted, and the front side end portion 11a of the concave mold 11 is configured as a free end.

  A front opening 17 that opens toward the convex unit 20 is formed between the front end 11a of the concave mold 11 and the front end 13a of the concave frame 13, and the concave mold 11 and the convex mold 21 are combined. Thus, the front opening 17 is closed by the convex unit 20, and the concave chamber 16 as a vapor chamber is formed in the concave housing 12 in a substantially airtight manner. The concave unit 10 is connected to a steam supply pipe 18a, a cooling water supply pipe 18b, and a drain pipe 18c that open into the concave chamber 16, and control valves 19a to 19c interposed in the middle of these pipes 18a to 18c. By operation, steam is supplied into the concave chamber 16 to heat and foam the foamable resin particles, or cooling water is sprayed from the nozzle 18d to the back side of the concave mold 11 to cool the molded product, or unnecessary drainage is removed. It can be discharged from the concave chamber 16. The concave mold 11 is formed with a large number of vent holes 11b, and steam is supplied from the concave mold chamber 16 into the molding space 2 through the vent holes 11b. The filling device 3 is fixed to the concave mold fixing plate 14, the tip of the filling device 3 is inserted into the molding space 2 through the concave mold 11, and the expandable resin particles are supplied from the filling device 3 into the molding space 2. Thus, the molding space 2 is filled. Although not shown, an ejector pin that can be inserted through the concave mold 11 and protrude into the molding space 2 through the concave mold 11 is supported.

  The convex housing 22 includes a rectangular cylindrical convex frame 23 provided so as to surround the convex mold 21, a convex fixing plate 24 that closes an opening on the back side of the convex frame 23, and a convex fixing plate 24. It has a rod-shaped fixing member 25 that fixes and supports the convex mold 21, and a center plate 27 that fixes the rear side end of the convex mold 21 to the convex frame 23. The center plate corresponds to the opening of the convex mold 21. An opening 27 b is formed in 27, and a convex chamber 26 is formed in the convex housing 22 on the back side of the convex mold 21 and the center plate 27.

  In a state where the concave mold 11 and the convex mold 21 are combined, the front opening 17 of the concave unit 10 is closed in a substantially airtight manner by the center plate 27 of the convex unit 20. A steam supply pipe 28a, a cooling water supply pipe 28b, and a drain pipe 28c that open into the convex chamber 26 are connected to the convex unit 20, and control valves 29a to 29a interposed in the middle of these pipes 28a to 28c. By operating 29c, steam is supplied into the convex chamber 26 to heat and foam the foamable resin particles, or cooling water is sprayed from the nozzle 28d to the back side of the convex mold 21 to cool the molded product, An unnecessary drain can be discharged from the convex chamber 26. A large number of vent holes 21b are formed in the convex mold 21, and steam is supplied from the convex chamber 26 into the molding space 2 through the vent holes 21b. However, it is possible to supply steam to the molding space 2 from other than the concave chamber 16 and the convex chamber 26. For example, the steam is supplied into the molding space 2 from the joint of the concave mold 11 and the convex mold 21, or a filling device. It is also possible to form a vent hole around the periphery of the ejector pin 3 and the ejector pin and supply steam into the molding space 2 from the vent hole.

  In the center plate 27, in a state where the concave mold 11 and the convex mold 21 are combined, a restricting portion 27a disposed outside the front side end portion 11a of the concave mold 11 is formed in a protruding shape, and this restricting portion 27a is used for molding. With the foaming pressure at, the front end 11a of the concave mold 11 is prevented from bulging outward. The restricting portion 27a can be formed in an annular shape corresponding to the entire circumference of the front side end portion 11a of the concave mold 11 or intermittently if the front side end portion 11a of the concave mold 11 can be prevented from bulging. It is also possible to provide it. Further, although the restricting portion 27 a is formed on the center plate 27, the restricting portion 27 a can be provided on the concave mold 11.

  A heat insulating material having a thermal conductivity of 2.5 kcal / m · h · ° C. or less is provided on substantially the entire inner surfaces of the convex housing 22 and the concave housing 12 and on substantially the entire outer surfaces of the convex housing 22 and the concave housing 12. It is provided so that further energy saving can be realized by reducing heat transfer to both housings 12 and 22 and reducing heat radiation from both housings 12 and 22. Insulating materials include silicon rubber, fluoro rubber, fluoro resin, polyethylene rubber, chloroprene rubber, butyl rubber, polyethylene, polypropylene, silicon resin, epoxy resin, carbon, polyvinylidene fluoride, polyether imide, polyphenyl sulfide, polyether ether ketone. , Polyamideimide or a composite material thereof can be employed. However, those in which one or both of the heat insulating materials on the inner surface or the outer surface of both housings 12 and 22 are omitted are also within the scope of the present invention.

  When a molded product is molded using this in-mold foam molding mold apparatus 1, the concave mold 11 and the convex mold 21 are closed to form the molding space 2, as in the conventional molding method. The molding space 2 is filled with the foamable resin particles by being put on the air flow from the filler 3. As a filling method of the expandable resin particles, a known filling method such as compression filling, pressure filling, cracking filling, or the like can be adopted.

  Then, steam is supplied from the concave chamber 16 to the convex chamber 26 through the molding space 2, steam is supplied from the convex chamber 26 through the molding space 2 to the concave chamber 16, At the same time, steam is supplied, the foamable resin particles are heated and foamed and fused in the molding space 2 to form a molded product, and then cooling water is sprayed to the back side of the concave mold 11 and convex mold 21. In addition, the molded product is cooled together with the concave mold 11 and the convex mold 21, and after cooling the molded product, the concave mold 11 and the convex mold 21 are opened to obtain a molded product.

  Thus, in this in-mold foam molding die apparatus 1, the concave mold 11 is supported in a cantilever manner on the concave housing 12, and the front surface that opens between the concave mold 11 and the concave housing 12 toward the convex unit 20 side. Since the opening 17 is formed, at least the center plate 30 of the concave unit 10 can be omitted. For this reason, the heat capacity of the mold apparatus 1 can be reduced by the amount that the center plate 30 is omitted, energy saving during molding can be realized, and the heating / cooling response speed of the mold apparatus 1 can be increased to improve the molding efficiency. Moreover, the number of parts of the mold apparatus 1 can be reduced, and the manufacturing cost of the mold apparatus 1 can be reduced. Further, since it is only necessary to omit the center plate 30 of the concave housing 12, the present invention can be easily applied to the existing mold apparatus 1 without making a significant design change.

(Second Embodiment)
Next, a mold apparatus 1A according to a second embodiment in which the configuration of the mold apparatus 1 is partially changed will be described. The same members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIGS. 3 and 4, the concave unit 10 of the mold apparatus 1A is configured in the same manner as the concave unit 10 of the first embodiment, and the convex housing 22A of the convex unit 20A is the first embodiment. Instead of the center plate 27 in the embodiment, a cover plate 27A for closing the opening on the back side of the convex mold 21 is provided for each convex mold 21, and the convex mold 21 and the cover plate 27A form a convex chamber 26A. The cover plate 27A and the convex mold 21 are fixedly supported by the convex fixed plate 24 in a cantilever manner via the fixing member 25, and the steam supply pipe 28a, the cooling water supply pipe 28b, and the drain pipe 28c are attached to each convex chamber 26A. They are connected individually.

  In this mold apparatus 1A, as in the mold apparatus 1 of the first embodiment, the center plate 30 of the concave unit 10 can be omitted. Therefore, energy saving can be realized during molding, and the mold apparatus 1 can be heated and cooled. Can improve the molding efficiency, reduce the number of parts of the mold apparatus 1A, and reduce the manufacturing cost of the mold apparatus 1A. In addition, since the small lid plate 27A is provided in place of the center plate 27 of the convex unit 20A, the heat capacity of the mold apparatus 1A can be set to be small by that amount, thereby realizing further energy saving. Further, since the center plate 30 is omitted for the concave housing 12, and only the cover plate 27A is provided instead of the center plate 27 for the convex housing 22A, a significant design change is made with respect to the existing mold apparatus. The present invention can be applied without performing the above.

(Third embodiment)
Next, a mold apparatus 1B according to a third embodiment in which the configuration of the mold apparatus 1 is partially changed will be described. The same members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIGS. 5 and 6, the concave unit 10 of the mold apparatus 1B is configured in the same manner as the concave unit 10 of the first embodiment, and the convex housing 22B of the convex unit 20B is the first embodiment. The center plate 27 and the fixing member 25 of the convex unit 20 in the form are omitted, the convex mold 21 is directly fixed to the convex fixing plate 24, and the concave mold 11 and the convex mold 21 are replaced with the restricting portion 27a. In a combined state, a restricting portion 24a disposed outside the front end portion 11a of the concave mold 11 is formed in a protruding shape on the convex fixing plate 24, and the concave mold 11 is outside by the foaming pressure during molding by the restricting portion 24a. And the opening on the back side of the convex mold 21 is closed by the convex fixing plate 24, and the convex chamber 26B is formed for each convex mold 21 by the convex mold 21 and the convex fixing plate 24. Formed, steam supply pipe 28a and cooling water The feed tube 28b and the drain pipe 28c which are connected individually to the respective convex chamber 26B.

  In this mold apparatus 1B, the center plates 30 and 27 of the concave unit 10 and the convex unit 20B can be omitted, and the fixing member 25 can also be omitted for the convex unit 20B. It can be set small to realize further energy saving. Moreover, by directly fixing the convex mold 2 to the convex fixing plate 24, the mold apparatus 1B can be configured to be small with respect to the mold opening / closing direction, and the capacity of the concave chamber 16 is somewhat larger than the conventional one. However, since the convex chamber 26B can be remarkably miniaturized, the amount of steam used can be reduced as a whole, and the surface areas of the inner and outer surfaces of both units 10 and 20B can be reduced. Can be realized.

The longitudinal cross-sectional view in the mold closed state of the mold apparatus for in-mold foam molding of a 1st embodiment Longitudinal sectional view of the mold device for foam molding in the same mold The longitudinal cross-sectional view in the mold closed state of the mold apparatus for in-mold foam molding of 2nd Embodiment Longitudinal sectional view of the mold device for foam molding in the same mold The longitudinal cross-sectional view in the mold closing state of the mold apparatus for in-mold foam molding of a 3rd embodiment Longitudinal sectional view of the mold device for foam molding in the same mold

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mold apparatus for in-mold foam molding 2 Molding space 3 Filler 10 Recessed unit 11 Recessed mold 11a Front end 11b Vent hole 12 Recessed housing 13 Recessed frame 13a Front end 14 Recessed fixed plate 15 Fixed member 16 Recessed chamber 17 Front opening 18a Steam supply pipe 18b Cooling water supply pipe 18c Drain pipe 18d Nozzle 19a to 19c Control valve 20 Convex unit 21 Convex 21b Vent hole 22 Convex housing 23 Convex frame 24 Convex fixing plate 25 Fixing member 26 Convex Mold chamber 27 Center plate 27a Restriction part 27b Opening 28a Steam supply pipe 28b Cooling water supply pipe 28c Drain pipe 28d Nozzle 29a-29c Control valve 30 Center plate 1A Mold device 20A Convex unit 22A Convex housing 26A Convex chamber 27A Cover plate 1B Mold device 20B Convex unit 22B Convex housing 24a Regulator 26B Convex chamber

Claims (6)

A concave unit having a concave mold and a concave housing that holds the concave mold unit, a concave unit having a concave chamber formed in the concave housing on the concave rear surface side, and a convex mold and a convex housing that holds the convex mold; A convex unit in which a convex chamber is formed in a convex housing on the side, and by combining both units, a foaming resin particle is filled into a molding space formed by the concave mold and the convex mold. A mold apparatus for in-mold foam molding in which foamable resin particles are heated and foam-fused to obtain a molded product,
Against the concave in a concave housing and the front end of the concave type is supported in a cantilever so that the free end, towards the convex unit side between the concave free end portion and recessed housing opening Forming a front opening, and in a state where the concave and convex are combined, the front opening is closed with a convex unit to make the concave chamber airtight,
A mold apparatus for in-mold foam molding.   The concave housing has a concave frame provided so as to surround the concave mold, a concave fixing plate that closes the opening on the back side of the concave frame, and a fixing member that fixes the concave mold to the concave fixing plate in a cantilevered manner, The mold apparatus for in-mold foam molding according to claim 1, wherein a front opening opening toward the convex unit side is formed between the concave mold and the concave frame.   The convex housing has a convex frame provided so as to surround the convex mold, and a convex fixing plate that closes an opening on the back side of the convex frame, and closes the convex rear opening. The mold apparatus for in-mold foam molding according to claim 1 or 2, wherein a convex mold is fixed to a convex mold fixing plate, and a convex mold chamber is formed on the back side of the convex mold.   The mold apparatus for in-mold foam molding according to any one of claims 1 to 3, wherein a restricting portion that restricts outward expansion of the concave free end portion is formed in the convex unit.   The in-mold foam molding according to any one of claims 1 to 4, wherein substantially the entire inner surface of the convex housing and the concave housing is covered with a heat insulating material having a thermal conductivity of 2.5 kcal / m · h · ° C or less. Mold equipment. The in-mold foam molding according to any one of claims 1 to 5, wherein substantially the entire outer surfaces of the convex housing and the concave housing are covered with a heat insulating material having a thermal conductivity of 2.5 kcal / m · h · ° C or less. Mold equipment.

Images