Method for manufacturing foam molding dies and foam molded products

Abstract

This technology provides an improved efficiency in removing burrs from foamed molded products. [Solution] The foam molding die 30 of this disclosure includes a recessed molding projection 40 that protrudes from the side surface of the cavity 33, and has a film molding section 39 between the overlapping portions 31K, 32K of the upper mold 31 and the lower mold 32 in the recessed molding projection 40. The film molding section 39 includes a first film molding section 44 that extends along the outer edge of the overlapping portions 31K, 32K in the recessed molding projection 40 that forms the boundary with the cavity 33, and a second film molding section 45 that is separated from the cavity 33 by the first film molding section 44. When the mold is closed, a larger gap is formed between the first and second molding dies 31, 32 than the gap between the first film molding section 44 and the second film molding section 45.

Description

Technical Field

[0001] The present disclosure relates to a foaming mold and a method for manufacturing a foamed molded product.

Background Art

[0002] Conventionally, it is known that burrs generated in a foamed molded product manufactured using a foaming mold are cut off with pliers, a cutter, etc. (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0016] , FIG. 4)

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a technique for improving the efficiency of the burr removal work for a foamed molded product.

Means for Solving the Problems

[0005] One aspect of the invention made to solve the above problems includes first and second mold halves that can be opened and closed, a cavity provided between the first and second mold halves for molding a foamed molded product, a recessed molding protrusion formed over the entire mold closing direction on a part of the side surface of the cavity and protruding in a direction intersecting the mold closing direction, and a film molding part formed between the overlapping parts of the first and second mold halves in the recessed molding protrusion. The film molding part includes a first film molding part extending along an outer edge part that becomes a boundary with the cavity among the overlapping parts in the recessed molding protrusion, and a second film molding part partitioned from the cavity by the first film molding part. The second film molding part forms a larger gap between the first and second mold halves than the first film molding part in the mold closed state, which is a foaming mold.

Brief Description of the Drawings

[0006] [Figure 1] Figure 1A is a perspective view of the foamed molded product according to the first embodiment, and Figure 1B is a side cross-sectional view of the foamed molded product. [Figure 2] Figure 2A is a plan view of the foamed molded product, and Figure 2B is a plan view of the foamed molded product before the finishing process. [Figure 3] Figure 3 is a perspective view of the foam molding die in the open state. [Figure 4] Figure 4 is a perspective view of the recessed molded protrusion. [Figure 5] Figure 5 is a cross-sectional view of the foam molding die in the closed state, which is section AA of Figure 4. [Figure 6] Figure 6A is a side cross-sectional view of the foam molding die with the foam resin material injected, and Figure 6B is a side cross-sectional view of the foam molding die with the foam resin material foamed and the cavity filled. [Figure 7] Figure 7 is a perspective view of a foamed molded product that integrally includes a membrane portion and a strip portion. [Figure 8] Figure 8A is a perspective view of the foamed molded product with the band portion removed, and Figure 8B is a perspective view of the foamed molded product with the membrane portion removed. [Figure 9] Figure 9 is a perspective view of a portion of the foam molding die of the second embodiment. [Figure 10] Figure 10A is a side cross-sectional view of the film-forming section, and Figures 10B to 10D are side cross-sectional views of the film-forming section relating to a modified example. [Modes for carrying out the invention]

[0007] [First Embodiment] A foam molding die 30 according to one embodiment of the present disclosure will be described with reference to Figures 1 to 8. Figure 1A shows a foam molded product 10 manufactured by the foam molding die 30. This foam molded product 10 is, for example, a seat pad used in the seating area of ​​the rear seat of a vehicle, and is foam molded with a base member 11 set in the cavity 33 of the foam molding die 30.

[0008] The base member 11 is, for example, a bead-foamed molded body made of polystyrene resin, polyolefin resin (polyethylene resin, polypropylene resin, etc.), and has a roughly rectangular parallelepiped shape that is elongated horizontally and flattened vertically. On the other hand, the foamed molded product 10 is, for example, made of soft polyurethane foam, and as shown in Figure 1B, covers the entire base member 11 except for the bottom surface. The foamed molded product 10 is finally covered on the surface with a surface material 19.

[0009] Furthermore, the foamed resin constituting the foamed molded product 10 in this embodiment is not limited to polyurethane resins, but can be any resin that can be foamed and molded. The foamed structure may be an open-cell structure with good ventilation, or a closed-cell structure without good ventilation. Moreover, although the foamed molded product 10 is an insert molded product enclosing the base member 11, it does not have to be an insert molded product. If it is an insert molded product, the enclosing component is not limited to resin, but may be made of metal. Also, although the base member 11, which is the enclosing component, is covered by the foamed molded product 10 on its entire surface except for the bottom surface, a part of the side or top surface of the base member 11 may be exposed from the foamed molded product 10.

[0010] Hereinafter, the up-and-down, left-and-right, and front-and-back directions of the foamed molded product 10, which is the seat pad, when it is attached to the vehicle will simply be referred to as "up-and-down, left-and-right, and front-and-back of the foamed molded product 10," and the structure of the required parts of the foamed molded product 10 will be described.

[0011] As shown in Figure 1A, the foamed molded product 10 has a planar shape that is, for example, a roughly elongated rectangle, and grooves 14 (hereinafter referred to as "front grooves 14") are formed at two locations on the front side in the lateral direction, dividing the foamed molded product 10 into three seats. Also, grooves 12 (hereinafter referred to as "rear grooves 12") are formed at two locations on the rear side of the foamed molded product 10 in the lateral direction, for receiving seat belt buckles. As shown in Figure 2A, the front grooves 14 have a gently curved contour shape and their depth in the front-to-back direction is shallower than their width in the lateral direction. In contrast, the rear grooves 12 have a roughly square cross-section, so-called square grooves, and penetrate the foamed molded product 10 vertically, with a depth that is, for example, approximately the same as or deeper than the width. In addition, stepped recesses 13 are formed on both sides of the foamed molded product 10 by recessing their rear ends in a stepped manner. These stepped recesses 13, like the grooves 12, are for receiving the seat belt buckle and have a shape that can be described as a V-groove.

[0012] As shown in Figure 1A, the parting line L of the foam molding die 30 in the foam molded product 10 is positioned along the outer edge of the lower surface of the foam molded product 10. Also, immediately after the foam molded product 10 is demolded from the foam molding die 30, as shown in Figure 2B, a burr 15 may protrude from the parting line L. In that case, the burr 15 is removed as shown in Figure 2A, and the manufacturing of the foam molded product 10 is completed.

[0013] In this embodiment, the foamed molded product 10 has a groove 14 on the front side, but it does not have to have a groove 14 on the front side. Also, the groove 12 on the rear side and the stepped recess 13 on the side are for receiving the seat belt buckle, but they may also be for receiving parts that secure the child seat.

[0014] The structure of the foam molding die 30 will be described in detail below. As shown in Figure 3, the foam molding die 30 comprises a lower mold 31 as the "first mold" and an upper mold 32 as the "second mold". The lower mold 31 is fixed, while the upper mold 32 is rotatably supported and superimposed on the lower mold 31 from above and below. That is, in the foam molding die 30 of this embodiment, the vertical direction is the mold closing direction and the mold opening direction, and the foam molded product 10 is molded in an inverted state within the foam molding die 30 (see Figure 6B). The upper mold 32 may be supported so as to move linearly in the vertical direction.

[0015] The cavity 33 of the foam molding die 30 is formed by closing the upper opening of the lower mold cavity 31A formed in the lower mold 31 with the upper mold 32. The outer surface of the foam molded product 10, excluding the bottom surface, is molded by the lower mold cavity 31A. From the side surface of the lower mold cavity 31A, a recess molding projection 40 for forming the groove portion 12 of the foam molded product 10, a recess molding bulge 40A for forming the groove portion 14, and a recess molding step portion 40B for forming the stepped recess 13 are projected. The upper mold 32 has a holding portion (not shown) for holding the base portion 11 in the portion facing the lower mold cavity 31A. The bottom surface of the foam molded product 10 is molded by the portion of the lower surface of the upper mold 32 that faces the lower mold cavity 31A and is not covered by the base portion 11.

[0016] On the overlapping portions 31K and 32K of the lower mold 31 and the upper mold 32 excluding the concave portion forming protrusions 40, seal portions 31L and 32L that abut against each other in the mold-closed state are provided along the boundary with the cavity 33. These seal portions 31L and 32L are formed so as to abut against each other in a surface-to-surface manner in the mold-closed state, and regulate the leakage of the foamed resin raw material outside the foaming mold 30. Also, a part of the seal portions 31L and 32L forms additional seal portions 34A and 34B according to the present disclosure, which will be described in detail later, and extends across the outer portion from each concave portion forming protrusion 40. Further, a plurality of gas vent grooves 35 are formed in the seal portion 31L of the lower mold 31 at positions avoiding the additional seal portion 34A. Then, by these gas vent grooves 35, the gas generated during foaming molding is discharged to the outside of the cavity 33, and finally the gas vent grooves 35 are blocked by the foamed resin raw material that has reached the upper part of the cavity 33.

[0017] As shown in FIG. 5, a film forming portion 39 is provided between the overlapping portions 31K and 32K of the lower mold 31 and the upper mold 32 in the concave portion forming protrusion 40. The film forming portion 39 is divided into a first film forming portion 44 along the outer edge portion that is the boundary with the cavity 33 among the overlapping portions 31K and 32K in the concave portion forming protrusion 40, and a second film forming portion 45 outside the cavity 33 than the first film forming portion 44. Specifically, as shown in FIG. 4, on the upper surface of the concave portion forming protrusion 40 of the lower mold 31, a bank portion 41 extending along the outer edge portion that is the boundary with the cavity 33 is provided, and the outside of the cavity 33 from the bank portion 41 is a recessed portion 42 that is recessed stepwise with respect to the bank portion 41. Also, the upper surface of the bank portion 41 is one step lower than the seal portion 31L. Then, as shown in FIG. 5, in the mold-closed state, the upper surface of the bank portion 41 and the lower surface of the upper mold 32 face each other with a gap therebetween, and the gap and the portions facing each other in the mold-closed direction across the gap form the first film forming portion 44. Also, in the mold-closed state, the bottom surface of the recessed portion 42 and the lower surface of the upper mold 32 face each other with a gap larger than the gap of the first film forming portion 44, and the gap and the portions facing each other in the mold-closed direction across the gap form the second film forming portion 45.

[0018] The first film forming part 44 has the upper surface shape of the embankment part 41 included in the first film forming part 44 forming a substantially U shape, and both ends thereof are connected to the seal parts 31L and 32L. And the part that linearly connects between the connection parts of the seal parts 31L and 32L with the first film forming part 44 forms the aforementioned additional seal parts 34A and 34B. And the second film forming part 45 is surrounded entirely by the additional seal parts 34A and 34B and the first film forming part 44, and is partitioned from the cavity 33 and the outside of the foam molding die 30.

[0019] The seal parts 31L and 32L including the additional seal parts 34A and 34B are designed to be in surface contact in the mold closed state, and there is no gap between the seal parts 31L and 32L. However, due to deterioration of the foam molding die 30 or the like, a slight gap (hereinafter simply referred to as "the gap that can occur in the seal parts 31L and 32L") may occur between the seal parts 31L and 32L in the mold closed state.

[0020] In the present embodiment, the gap of the first film forming part 44 is, for example, 0.1 to 0.5 mm, and the gap of the second film forming part 45 is, for example, 1.0 to 5.0 mm. Also, the width of the first film forming part 44 (that is, the width of the embankment part 41) is, for example, 2.0 to 5.0 mm. Regarding the seal parts 31L and 32L and the additional seal parts 34A and 34B as well, for example, an embankment part 41 with a width of 2.0 to 5.0 mm may be formed.

[0021] From the bottom of the recessed part 42, a pair of latching hole forming parts 43 project. As shown in FIG. 4, the pair of latching hole forming parts 43 form, for example, a columnar shape with an elliptical cross section that is long in the direction in which the protrusion 40 for forming a recess projects from the side surface of the cavity 33. Also, the pair of latching hole forming parts 43 are arranged closer to the base end side of the recess forming protrusion 40, in other words, the side closer to the additional seal part 34A among the recess forming protrusions 40. Further, the upper surface of the latching hole forming part 43 is located at the same height as the upper surface of the seal part 31L of the lower mold 31, and is in surface contact with the lower surface of the upper mold 32 in the mold closed state.

[0022] In this embodiment, the number of latching hole forming portions 43 provided in the recessed forming projection 40 is two, but it may be one or three or more. Also, the plan view shape of the latching hole forming portion 43 is not limited to an ellipse, but may be circular or rectangular, for example. Furthermore, the latching hole forming portion 43 is preferably located near the base end of the recessed forming projection 40, but is not limited to that, and may be located in the center or near the tip of the recessed forming projection 40.

[0023] This concludes the description of the structure of the foamed molded product 10 and the foaming mold 30 in this embodiment. The manufacturing method of the foamed molded product 10 will now be described. The manufacturing method includes a molding process for the foamed molded product 10 using the foaming mold 30 and a finishing process performed on the foamed molded product 10 after demolding from the foaming mold 30. First, the molding process will be described with reference to Figures 6A and 6B.

[0024] As shown in Figure 6A, the base portion 11 is set in the holding portion of the upper mold 32 of the foam molding die 30 in the open state, and the foam resin material G is injected into the lower mold cavity 31A of the lower mold 31. At this time, the foam resin material G is poured over the upper surface of the recessed molding protrusion 40 on the lower mold 31 side and accumulates in the recessed portion 42.

[0025] Next, the foam molding die 30 is closed, and the lower mold cavity 31A of the lower mold 31 is closed by the upper mold 32 to form a cavity 33. At the same time, the lower surface of the upper mold 32 is placed on top of the upper surface of the recessed molding projection 40 of the lower mold 31, and a film molding section 39 is formed between them. As this mold closed state is maintained, the foam resin raw material G accumulated at the bottom of the lower mold cavity 31A foams and expands. Consequently, the air inside the cavity 33 is released, and the foaming gas is discharged to the outside through the vent groove 35. Then, the cavity 33 is filled with foam, and the foamed molded product 10 is formed (see Figure 6B).

[0026] At this time, the foamed resin raw material G that has been poured over the upper surface of the recessed molding protrusion 40 and accumulated in the recessed portion 42 also foams and expands, filling the inside of the film molding section 39 with foam, and the film portion 17 is formed by the film molding section 39. In addition, the foamed resin raw material G either overflows from the film molding section 39 to the cavity 33 side, or the foam enters from the cavity 33 to the film molding section 39 side, thereby integrally molding the foamed molded product 10 and the film portion 17.

[0027] More specifically, as shown in Figure 7, the membrane portion 17 consists of an outer thin-walled portion 17A formed by the bank portion 41 of the recessed molding protrusion 40 and an inner thick-walled portion 17B formed by the recessed portion 42, with the outer thin-walled portion 17A being thinner than the inner thick-walled portion 17B. In addition, a pair of latching holes 18 corresponding to a pair of latching hole molding portions 43 are formed in the inner thick-walled portion 17B.

[0028] Furthermore, the foamed resin material G that reaches the top of the cavity 33 enters the gas vent groove 35. The foamed resin material G that enters the gas vent groove 35 becomes a strip portion 16, which is integrally molded to protrude from the parting line of the foamed molded product 10. If a gap occurs in the seal portions 31L and 32L, the foamed resin material G that enters that gap becomes a burr 15.

[0029] This concludes the explanation of the molding process for the foamed molded product 10. Next, the finishing process for the foamed molded product 10 will be explained. In the finishing process, the burrs 15, strip portion 16, and film portion 17 generated during molding are removed from the foamed molded product 10. Specifically, first, the burrs 15 and strip portion 16 are removed from the foamed molded product 10 using a cutting tool such as a cutter. Figure 8A shows a magnified view of a part of the foamed molded product 10 from which the burrs 15 and strip portion 16 have been removed. At this time, the groove portion 14 and stepped recess portion 13 (see Figure 1) on the front side of the foamed molded product 10 are relatively shallow, and it is easy to maneuver a cutting tool inside them, so the burrs 15 generated inside them are also removed with the cutting tool.

[0030] On the other hand, it is difficult to maneuver a cutting tool inside the relatively deep groove 12 at the rear of the foamed molded product 10. However, in the foamed molded product 10 molded by the foamed molding die 30 of this embodiment, a film portion 17 is formed inside the rear groove 12. This film portion 17 can be easily removed from the foamed molded product 10 by pulling it. Specifically, if the overlapping portions 31K, 32K of the lower mold 31 and upper mold 32 in the recessed molding projection 40 that molds the inside of the rear groove 12 are composed of sealing portions 31L, 32L, then the burr 15 generated by the foamed resin raw material G applied to the recessed molding projection 40 becomes a very thin film, and when the burr 15 is pulled, it partially breaks and remains on the foamed molded product 10 side, forcing the worker to pull and remove the burr 15 inside the groove 12 multiple times. Moreover, because the groove 12 is deep, it is difficult to insert a hand or gripping tool to the bottom of the groove 12. In contrast, the membrane portion 17 has an outer edge (boundary with the foamed molded product 10) which is a thin outer edge portion 17A, and an inner portion which is a thick inner portion 17B. Therefore, when the thick inner portion 17B is pulled, as shown in Figure 8B, only the thin outer edge portion 17A breaks and the entire membrane portion 17 is removed from the foamed molded product 10 at once. Furthermore, a retaining hole 18 is formed in the thick inner portion 17B, so the membrane portion 17 can be easily removed by hooking a fingertip or tool into the hole and pulling. Moreover, the retaining hole 18 is positioned close to the opening side of the groove portion 12 of the membrane portion 17, so it is easy to hook a finger or the like into the retaining hole 18. With the membrane portion 17 removed, the manufacturing of the foamed molded product 10, including the finishing process, is completed.

[0031] As described above, when the foam molding die 30 of this embodiment is used, a film portion 17 is formed inside the deep groove portion 12 of the foam molded product 10 by the film forming portion 39, instead of the burrs 15. The film forming portion 39 includes a first film forming portion 44 that extends along the outer edge which forms the boundary with the cavity 33 in the recessed molding protrusion 40, and a second film forming portion 45 that is outside the cavity 33. The second film forming portion 45 is configured such that when the mold is closed, the gap between the lower mold 31 and the upper mold 32 is larger than that of the first film forming portion 44. As a result, the film portion 17 is thin at the outer edge (the boundary with the foam molded product 10) and thicker inside the outer edge (outside the foam molded product 10), so that only the outer edge of the film portion 17 breaks when an external force is applied to the film portion 17, and the entire film portion 17 can be easily separated from the inner surface of the groove portion 12. In other words, according to the foam molding die 30 of this embodiment, the difficult task of removing burrs in the grooves 12 of the foam molded product 10 is reduced, and the efficiency of burr removal work on the foam molded product 10 is improved.

[0032] Furthermore, in the foam molding die 30 of this embodiment, the overlapping portions 31K and 32K, excluding the recessed molding protrusion 40, are provided with sealing portions 31L and 32L that abut each other at the boundary with the cavity 33 when the mold is closed. In conventional foam molding dies, a sealing portion is also provided at the boundary with the cavity 33 in the recessed molding protrusion 40, but in this embodiment, the first film molding portion 44 of the film molding portion 39 is provided there, so there is a concern that the foam resin raw material G may leak out of the foam molding die 30 from the first film molding portion 44. However, in the foam molding die 30 of this embodiment, additional sealing portions 34A and 34B connect the connection portions of the first film molding portion 44 and the sealing portions 31L and 32L, and together with the first film molding portion 44, surround the second film molding portion 45. As a result, the additional sealing parts 34A and 34B can prevent the foamed resin raw material G from leaking out through the gap between the lower mold 31 and the upper mold 32 in the film molding section 39. Furthermore, even if burrs 15 are generated on the sealing parts 31L and 32L and the additional sealing parts 34A and 34B, the additional sealing parts 34A and 34B form part of the sealing parts 31L and 32L and are continuous with the sealing parts 31L and 32L on the outside of the groove 12 in the foamed molded product 10. Therefore, the burrs 15 from the additional sealing parts 34A and 34B can be removed with a cutting tool in the same way as the burrs 15 from the sealing parts 31L and 32L.

[0033] Furthermore, since the film molding section 39 of this embodiment is provided with a recessed section 42 on the lower mold 31 side, foam resin raw material G can be poured into the recessed section 42 and stored in the molding process of the foam molded product 10, thereby ensuring a stable supply of foam resin raw material G to form the film section 17.

[0034] [Second Embodiment] The foam molding die 30 of the second embodiment of the present disclosure shown in Figure 9 differs from the first embodiment in that it is provided with a recess 46 for forming a protrusion instead of the locking hole molding portion 43 described in the first embodiment. The recess 46 for forming a protrusion is formed as a recess at the bottom of the recessed portion 42, for example, and is positioned towards the base end side of the recess-forming protrusion 40. Furthermore, the recess 46 for forming a protrusion has a rectangular shape in plan view, which is elongated in the direction in which the recess-forming protrusion 40 protrudes from the side surface of the cavity 33.

[0035] By providing a recess 46 for forming a protrusion, a gripping portion that can be grasped with a finger is formed on the film portion 17. Specifically, during the molding process, when the foamed resin raw material G is injected, the foamed resin raw material G placed on the recessed protrusion 40 enters the recess 46 for forming the protrusion and foams, thereby forming a gripping portion that protrudes from the inner thickened portion 17B of the film portion 17. As a result, the film portion 17 can be removed by pinching and pulling the gripping portion during the deburring process.

[0036] The recess 46 for forming the protrusion does not have to be rectangular in plan view; for example, it may be circular or other polygonal in shape. Also, the recess 46 for forming the protrusion may be located on the protruding end side of the recess-formed protrusion 40, rather than the base end side, or it may be located at an intermediate position in the protruding direction. If the recess 46 for forming the protrusion is provided on one end side of the recess-formed protrusion 40 in the protruding direction, the film portion 17 can be removed by pinching it and peeling off the lid, making the removal work easier. Furthermore, this recess 46 for forming the protrusion may be formed together with the latching hole forming portion 43 of the first embodiment.

[0037] <Other Embodiments> The foam molding die 30 of the first and second embodiments may be modified, for example, as shown in (1) to (10) below. (1) In the above embodiment, the ridge portion 41 of the recessed molding protrusion 40 was separated from the lower surface of the upper mold 32 by the gap of the first film molding portion 44. However, multiple contact portions may be provided on the ridge portion 41 so that it partially contacts the lower surface of the upper mold 32. In this way, the thin outer edge portion 17A of the film portion 17 becomes a so-called cut line, making it easier to remove the film portion 17.

[0038] (2) In the above embodiment, the recessed molding projection 40 having the film-forming portion 39 was substantially rectangular in plan view, but is not limited to that, and may be semicircular, triangular, or other polygonal shapes, for example.

[0039] (3) In the above embodiment, the film forming section 39 is provided so that the film portion 17 is formed only in the groove portion 12, which is relatively deep and where it may be difficult to work with a cutting tool, among the groove portions 12, 14 and stepped recess 13 which can be called a V-groove provided in the foamed molded product 10. However, the film forming section 39 may be provided so that the film portion 17 is formed in all grooves regardless of depth.

[0040] (4) In the foam molding die 30 of the above embodiment, the lower mold 31 and the upper mold 32 in the first film molding section 44 of the film molding section 39 were structured so that they could not come into contact when the mold was closed. However, similar to the sealing sections 31L and 32L, the lower mold 31 and the upper mold 32 in the first film molding section 44 may be structured so that they can come into contact when the mold is closed, and an outer edge thin-walled section 17A of the same thickness as the burr 15 may be formed. That is, the opposing surfaces of the lower mold 31 and the upper mold 32 in the first film molding section 44 of the film molding section 39 may be surfaces that are continuous with the sealing sections 31L and 32L.

[0041] (5) In the above embodiment, the embankment portion 41 and the recessed portion 42 included in the film forming portion 39 were formed on the upper surface of the recessed forming projection 40 of the lower mold 31, but they may also be formed on the lower surface of the upper mold 32 in the portion facing the recessed forming projection 40. Specifically, for example, as shown in Figure 10D, the upper surface of the recessed forming projection 40 may be made flat, and the lower surface of the upper mold 32 may be provided with a recessed portion 42Z by recessing the portion inside the outer edge along the boundary with the cavity 33 in the area facing the upper surface of the recessed forming projection 40 when the mold is closed.

[0042] (6) The foamed molded product 10 formed in the foam molding die 30 of the above embodiment was a seat pad, but is not limited to that, and can be any foamed molded product, and does not have to be an automobile part.

[0043] (7) In the above embodiment, the foam molding die 30 comprises a lower mold 31 and an upper mold 32 as first and second molding dies, with a film forming section 39 provided between them. However, the foam molding die 30 may also have a structure comprising three molding dies: an upper mold, a lower mold, and a middle mold, and any two of these molding dies may be designated as the first and second molding dies and provided with the film forming section 39.

[0044] (8) In the above embodiment, the gas vent groove 35 was positioned to avoid the additional seal portion 34A, but the gas vent groove 35 may be positioned in the additional seal portion 34A so that the film portion 17 and the strip portion 16 are molded together.

[0045] (9) In the first embodiment, the embankment portion 41 of the recessed molded projection 40 had a rectangular cross-section as shown in Figure 10A, and a stepped structure was formed between the embankment portion 41 and the recessed portion 42. However, for example, as shown in Figure 10B, the embankment portion 41B of the recessed molded projection 40 may have an inclined portion 47 on the side of the recessed portion 42.

[0046] (10) Alternatively, as shown in Figure 10C, the cross-sectional shape of the embankment portion 41C may be a trapezoidal shape with a pair of inclined surfaces, and the lower surface of the upper mold 32 may be provided with an inclined surface parallel to the outer inclined surface of the embankment portion 41C.

[0047] <Note> The following describes the features extracted from the above embodiment, explaining their effects and other aspects as needed. For ease of understanding, corresponding configurations in the above embodiment will be indicated in parentheses as appropriate, but these features are not limited to the specific configurations indicated in parentheses.

[0048] [Feature 1] A first and second mold (31, 32) that can be opened and closed, a cavity (33) provided between the first and second mold (31, 32) for molding a foamed molded product (10), a recessed molding projection (40) formed on a part of the side surface of the cavity (33) over the entire direction of the mold closing direction and projecting in a direction intersecting the direction of the mold closing direction, and a film molding portion (39) formed between the overlapping portions (31K, 32K) of the first and second mold (31, 32) in the recessed molding projection (40), The film forming section (39) includes a first film forming section (44) that extends along the outer edge of the overlapping section (31K, 32K) in the recess forming protrusion (40) which forms the boundary with the cavity (33), and a second film forming section (45) that is separated from the cavity (33) by the first film forming section (44), wherein the second film forming section (45) is a foam molding die (30) in which, when the mold is closed, the gap between the first and second molding dies (31, 32) is larger than that between the first film forming section (44).

[0049] When using the foam molding die (30) of Feature 1, a film portion (17) is formed inside the deep groove portion (12) of the foam molded product (10) by the film forming portion (39). The film forming portion (39) includes a first film forming portion (44) that extends along the outer edge which forms the boundary with the cavity (33) in the recessed molding protrusion (40), and a second film forming portion (45) located inside it. The second film forming portion (45) is configured such that, in the closed state, the gap between the first and second molds (31, 32) is larger than that between the first film forming portion (44). As a result, the outer edge of the film portion (17) is thinner and the area inside the outer edge is thicker, so that by applying an external force to the film portion (17), only the outer edge of the film portion (17) breaks, and the entire film portion (17) can be easily separated from the inner surface of the groove portion (12). In other words, with the foam molding die (30) of Feature 1, the difficult task of removing burrs in the grooves (12) of the foam molded product (10) is reduced, and the efficiency of burr removal work on the foam molded product (10) is improved.

[0050] [Feature 2] The overlapping portions (31K, 32K), excluding the recessed molding protrusion (40), are provided with sealing portions (31L, 32L) that abut each other at the boundary with the cavity (33) when the mold is closed, and the first film molding portion (44) has both ends connected to the sealing portions (31L, 32L), and additional sealing portions (34A, 34B) that connect the connection portions of the first film molding portion (44) and the sealing portions (31L, 32L), and surround the second film molding portion (45) together with the first film molding portion (44), and in the mold closed state, the first film molding portion (44) forms a larger gap than the additional sealing portions (34A, 34B), as described in Feature 1 of the foam molding die (30).

[0051] In the foam molding die (30) of Feature 2, the overlapping portions (31K, 32K), excluding the recessed molding protrusion (40), are provided with sealing portions (31L, 32L) that abut each other at the boundary with the cavity (33) when the mold is closed. In conventional foam molding dies, a sealing portion is also provided at the boundary with the cavity (33) in the recessed molding protrusion (40). However, in the configuration of Feature 2, the first film molding portion (44) of the film molding portion (39) is provided there, so there is a concern that foam resin material may leak out of the foam molding die (30) from the first film molding portion (44). However, in the foam molding die (30) of this embodiment, additional sealing portions (34A, 34B) connect the connection portions of the first film molding portion (44) and the sealing portions (31L, 32L), and together with the first film molding portion (44), surround the second film molding portion (45). As a result, the additional sealing parts (34A, 34B) can prevent foam resin material from leaking out through the gap between the first and second molds (31, 32) in the film molding section (39). Furthermore, even if burrs (15) form on the sealing parts (31L, 32L) and the additional sealing parts (34A, 34B), since the additional sealing parts (34A, 34B) are continuous with the sealing parts (31L, 32L), the burrs (15) on the additional sealing parts (34A, 34B) can be removed with a cutting tool in the same way as the burrs (15) on the sealing parts (31L, 32L).

[0052] Alternatively, the burrs (15) from the sealing parts (31L, 32L) and additional sealing parts (34A, 34B) may be removed from the foamed molded product (10) and the membrane part (17), and then the membrane part (17) may be removed from the foamed molded product (10). Alternatively, the burrs (15) from the sealing parts (31L, 32L) and additional sealing parts (34A, 34B) may be cut only from the foamed molded product (10) without cutting from the membrane part (17), and the membrane part (17) with the burrs (15) attached may be removed from the foamed molded product (10).

[0053] [Feature 3] The foam molding die (30) according to feature 1 or 2, wherein the overlapping portions (31K, 32K) in the recessed molding protrusion (40) are provided with locking hole molding portions (43) that abut each other in a portion inward from their outer edges.

[0054] When using the foam molding die (30) of Feature 3, a retaining hole (18) is formed in the thicker portion of the membrane (17) inside the outer edge by the retaining hole forming section (43). Then, the membrane (17) can be pulled out by placing a finger or tool on the retaining hole (18) and removed from the foam molded product (10).

[0055] [Feature 4] The aforementioned latching hole forming portion (43) is positioned near the base end of the recess forming projection (40) in the foam molding die (30) according to feature 3.

[0056] When using the foam molding die (30) of Feature 4, the retaining hole (18) is positioned closer to the outside of the groove (12) within the membrane portion (17), making it easier to grip the retaining hole (18) with a finger or tool, thereby improving the efficiency of the removal work of the membrane portion (17).

[0057] [Feature 5] A foam molding die (30) according to any one of the features 1 to 4, wherein at least one of the overlapping portions (31K, 32K) in the recessed molding protrusion (40) is provided with a recess for forming a protrusion (46) in which a part of the portion inside the outer edge is recessed.

[0058] When using the foam molding die (30) of Feature 5, a tensile projection is formed in the thicker portion of the membrane (17) inside the outer edge by the projection forming recess (46). Then, the membrane (17) can be pulled by pinching the tensile projection and removed from the foam molded product (10).

[0059] [Feature 6] The foam molding die (30) according to feature 5, wherein the recess (46) for forming the protrusion is formed to be elongated in a direction intersecting the mold closing direction.

[0060] When using the foam molding die (30) of Feature 6, the tensile projection formed by the projection forming recess (46) extends in a direction intersecting the mold closing direction, making it easier to grasp.

[0061] [Feature 7] A foam molding die (30) according to any one of features 1 to 6, wherein a plurality of hole-forming sections are dispersed in the first film-forming section (44) and are in contact with each other when the mold is closed, and a gap of the same height as the plurality of hole-forming sections is formed in the first film-forming section (44).

[0062] When using the foam molding die (30) of Feature 7, multiple holes are formed in the thin-walled outer edge portion of the membrane portion (17) by the multiple hole forming portion. This makes the outer edge of the membrane portion (17) easier to break, and makes it easier to remove the membrane portion (17) from the foam molded product (10).

[0063] [Feature 8] A method for manufacturing a foamed molded product (10), comprising using a foamed molding die (30) described in any one of the features 1 to 7, to produce a foamed molded product (10).

[0064] According to the manufacturing method of the foamed molded product (10) of Feature 8, since the foamed molding die (30) described in any one of Feature 1 to 7 above is used, the difficulty of removing burrs in the grooves (12) of the foamed molded product (10) is reduced, and the efficiency of removing burrs from the foamed molded product (10) is improved.

[0065] [Feature 9] A method for manufacturing a foamed molded product (10) using a foaming mold (30) described in Feature 3 or 4, wherein when injecting foaming resin raw material into the cavity (33), the foaming resin raw material is applied to one of the overlapping portions (31K, 32K) in the recessed molding protrusion (40) before closing the mold to form the foamed molded product (10), and after opening the mold, the film formed by the film forming portion (39) is pulled out using the hole (18) formed by the locking hole forming portion (43) and removed from the foamed molded product (10).

[0066] According to the manufacturing method of the foamed molded product (10) of Feature 9, a retaining hole (18) is formed in the thicker portion of the membrane (17) inside the outer edge by the retaining hole forming section (43) of the foaming mold (30). Then, the membrane (17) can be pulled out by placing a finger or tool on the retaining hole (18) and removed from the foamed molded product (10).

[0067] [Feature 10] A method for manufacturing a foamed molded product (10) using a foaming mold (30) described in Feature 5 or 6, wherein when injecting foaming resin raw material into the cavity (33), the foaming resin raw material is applied to one of the overlapping portions (31K, 32K) in the recessed molding protrusion (40) before closing the mold to form the foamed molded product (10), and after opening the mold, the protrusion formed by the protrusion forming recess (46) is used to pull the film formed by the film forming portion (39) and remove it from the foamed molded product (10).

[0068] According to the manufacturing method of the foamed molded product (10) of Feature 10, a tensile projection is formed in the thicker portion of the membrane (17) inside the outer edge by the projection-forming recess (46) of the foaming mold (30). Then, the membrane (17) can be pulled by pinching the tensile projection and removed from the foamed molded product (10).

[0069] While this specification and drawings disclose specific examples of the technology included in the claims, the technology described in the claims is not limited to these specific examples, but also includes various modifications and changes to these examples, as well as parts of the examples taken individually. [Explanation of symbols]

[0070] 10 Foamed molded products 18 Latch hole 30 Foam molding dies 31 Lower mold (first molding mold) 31A Lower Cavity 31K, 32K overlapping section 31L, 32L sealing section 32 Upper mold (second molding mold) 33 Cavity 34A, 34B Additional sealing section 39 Membrane forming section 40 Recessed molded protrusion 43 Latching hole molding part 44 1st membrane forming section 45 2nd membrane forming section 46 Recess for forming protrusions

Claims

1. Openable and closable first and second molding dies, A cavity is provided between the first and second molds for molding a foamed product, A recessed molding projection is formed on a part of the side surface of the cavity, extending over the entire length in the mold closing direction and protruding in a direction intersecting the mold closing direction, The recessed molding protrusion comprises a film forming portion formed between the overlapping portions of the first and second molds, The film forming portion includes a first film forming portion that extends along the outer edge of the overlapping portion in the recess forming protrusion which forms the boundary with the cavity, and a second film forming portion that is separated from the cavity by the first film forming portion. The second film molding section is a foam molding die in which, when the mold is closed, the gap between the first and second molds is larger than that between the first film molding section.

2. The overlapping portion, excluding the recessed molding protrusion, is provided with a sealing portion that abuts against each other at the boundary with the cavity when the mold is closed. The first film forming section is connected at both ends to the sealing section, It has an additional sealing portion that connects the connection portions of the first film forming portion and the sealing portion, and surrounds the second film forming portion with the first film forming portion, The foam molding die according to claim 1, wherein, in the closed state, the first film molding portion forms a larger gap than the additional sealing portion.

3. The foam molding die according to claim 2, wherein the overlapping portion of the recessed molding protrusion is provided with a locking hole molding portion that abuts against each other in a part of the second film molding portion surrounded by the first film molding portion and the additional sealing portion.

4. The foam molding die according to claim 3, wherein the retaining hole forming portion is positioned near the base end of the recess forming projection.

5. The foam molding die according to claim 2, wherein at least one of the overlapping portions in the recessed molding protrusion is provided with a recess for forming a protrusion, which is formed by indenting a part of the second film molding portion surrounded by the first film molding portion and the additional sealing portion.

6. The foam molding die according to claim 5, wherein the recess for forming the protrusion is formed to be elongated in a direction intersecting the mold closing direction.

7. A method for manufacturing a foamed molded product, comprising using a foaming mold described in any one of claims 1 to 6.

8. A method for manufacturing a foamed molded product using a foaming mold described in claim 3 or 4, When injecting foamed resin raw material into the cavity, The foamed resin material is applied to one of the overlapping portions in the recessed molding protrusion, and then the mold is closed to form the foamed molded product. A method for manufacturing a foamed molded product, comprising using the holes formed by the retaining hole forming section after the mold is opened to pull the film formed by the film forming section and remove it from the foamed molded product.

9. A method for manufacturing a foamed molded product using a foaming mold described in claim 5 or 6, When injecting foamed resin raw material into the cavity, The foamed resin material is applied to one of the overlapping portions in the recessed molding protrusion, and then the mold is closed to form the foamed molded product. A method for manufacturing a foamed molded product, comprising using the protrusions formed by the recesses for forming the protrusions after the mold is opened to pull the film formed by the film forming section and remove it from the foamed molded product.

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