JPH11309735A - Mold apparatus for foam molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent unevenness of filling density of raw material beads and unevenness of heating and cooling from being generated in the inside of a cavity through which services such as compressed air hardly pass by providing individual openings for the services at parts where circulation of the services becomes uneven and providing passages communicating with the external service pipelines on the openings. SOLUTION: In a pair of combined molds 51 and 61 formed under a condition where they surround a cavity for forming a foamed molded body, a slit 7a exposed in the cavity 4 is arranged along the joint part of the combined molds 51 and 61. As passages communicating between the slit 7a and an opening 73a for service connected with external service pipelines, a passage between the molds and an internal pipeline 72a are provided. In addition, individual openings for the services are arranged at parts where circulation of the services becomes uneven in the cavity 4, e.g. the apex parts of the second cavities 41 and 42 with a bag-like crosssection formed in the inner faces of the molds 51 and 61 and pipelines 41a and 42a are provided on the openings as passages communicating with the external service pipelines.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foam molding die apparatus used for foam molding for producing a heat insulating container or construction material made of expanded polystyrene resin or the like, or a heat insulating floor substrate. In particular, the present invention relates to an improvement of a utility supply structure provided in the foam molding die apparatus.

[0002]

2. Description of the Related Art An outline of a mold apparatus used in a foam molding method as a background of the present invention will be described. As shown in a schematic sectional view of FIG. The convex mold 31 and the concave mold 21 are arranged to face each other, and the concave mold 21 is usually fixed. However, the convex mold 31 has the cavity 1 in the concave mold 21 as shown in FIG. It is arranged so as to move horizontally (to the right in FIG. 5) from the formed state and to take out the molded foam. And this mold 2
Numerous vent holes 22 and 32 are formed in 1 and 31 so that utilities such as heating steam described later can pass through.

A concave chamber 2 and a convex chamber 3 to which utilities such as steam are supplied are formed on the back side of the concave and convex molds 21 and 31. In this case, upper chambers 24 and 34 for supplying steam for heating and the like are provided at the upper part of each chamber 2 and 3, and lower chambers 25 and 35 are provided at the lower part. And
It is connected to a decompression pump or drain pipe.

[0004] Using such a mold apparatus for foam molding,
After filling the cavity 1 with the pre-foamed raw material beads, the foam is evacuated under reduced pressure, heated by steam for heating, foamed, fused, and further cooled and solidified to form a foamed foam made of a predetermined foamed polystyrene resin or the like. The vent holes 22 and 32 formed in the mold in the foam molding are used as a discharge passage for air between the raw material beads or as a supply passage for heated steam. It plays an important role in gaining, but the following problems were also recognized.

(1) As a mold, a thick aluminum alloy material is used to compensate for a decrease in strength due to a large number of core vent mounting holes, and the heat capacity is large, the heat efficiency of heating and cooling is inferior, and the temperature control accuracy is low. There was a problem. (2) An enormous number of core vent attachment holes need to be drilled and core vents must be manually attached,
It took time to make.

(3) Since a problem such as clogging of the vent hole occurs, maintenance work such as replacement or periodic cleaning with high-pressure cleaning water is required. (4) Since traces of core vents and vent holes are formed on the surface of the molded product, it is inconvenient in operations such as printing on the surface and attaching a seal label. (5) Since the cooling water permeates the cavities in the cooling step and moistens the molded product, a drying step is required.

[0007]

The applicant of the present invention has previously proposed a foam molding die apparatus which can solve such problems as Japanese Patent Application No. 10-86267. According to the present invention, when the new foam molding die apparatus is put to practical use, unevenness in the packing density of the raw material beads, unevenness in heating and cooling, etc. in the cavity inside the cavity where tools such as compressed air are difficult to flow is prevented. Therefore, there is provided a mold apparatus for foam molding having a newly added structure.

[0008]

SUMMARY OF THE INVENTION A first aspect of the present invention, which has been made to solve the above problems, is a foam molding die apparatus which surrounds a cavity for forming a foamed article. In a pair of combined molds to be formed, a slit exposed in the cavity is provided along a joint portion of the combined mold, and the slit is provided with a passage communicating with an external utility pipe, In the cavity, individual utility openings are provided at portions where the distribution of utilities is uneven, and the openings are provided with passages communicating with external utility pipes. .

In the first invention, an individual utility opening is provided at the tip of a second cavity having a bag-shaped cross section formed on the inner surface of the mold, and an external utility opening is provided in the opening. This can be embodied in a form in which a passage communicating with the utility pipe is provided.

[0010] A foam molding die apparatus according to a second invention of the present invention is a pair of combined dies formed in a state surrounding a cavity for forming a foam molded article.
A pair of slits exposed in the cavity are provided at positions facing each other across the cavity along the joint portion of the combination mold, and each slit has a passage communicating with an external utility pipe. In addition to the above, when the interval between the slits is 100 mm or more, an individual utility opening is provided on a mold surface at an intermediate position between the slits and a passage communicating with an external utility pipe. It is characterized by having been provided.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a foam molding die apparatus according to the present invention will be described with reference to FIGS. First, the structure of the mold apparatus of the first invention is shown in FIG.
As in the conventional case, the convex mold 61 and the concave mold 51 are arranged to face each other so as to surround and form the cavity 4 in which the foam molded body is filled and molded. In addition, this concave mold 51
Is fixed and cannot move, but the convex mold 61 moves horizontally (to the right in FIG. 1) from the state in which the cavity 4 is formed in the concave mold 51 as shown in FIG. It is movably arranged so that the foamed molded product can be taken out.

Frames 52, 62 and back plates 53, 63 are attached to the back side of the dies 51, 61, and the concave side chamber 5 and the convex side chamber 6 to which utilities such as steam are supplied are provided. Is formed. In this case, in the upper part of the frames 52 and 62, the upper use opening 54,
A lower valve 55 is provided at a lower portion, and a steam valve to which steam for heating is supplied is attached to the upper port 54, 64, respectively. , 65 are provided with a pressure reducing pump or a valve connected to a drain pipe.

The first feature of the present invention resides in that, first, a pair of combined molds 51 and 61 formed so as to surround a cavity for forming a foamed molded body as described above. In the combination molds 51, 61
The slits 7a and 7b exposed in the cavity 4 are provided along the joint portion of
Utility port 73 connected from a, 7b to an external utility pipe
a, 73b as a passage for communicating between
a, 71b and internal pipes 72a, 72b.

That is, when the mold is closed, the mold 51,
61 is not provided with a vent hole as in the prior art, and the cavity 4 has a concave chamber 5 and a convex chamber 6.
And at the same time, slits 7a and 7b communicating with the service ports 73a and 73b to the outside are formed, and supply of steam, supply of compressed air, and exhaust for vacuum decompression are formed in the cavity 4. Alternatively, it is configured such that utility operations such as pressure adjustment in the cavity and discharge of drain can be individually performed.

Further, the second feature is that, at the same time, as shown in FIG. 2 showing the upper half of the cross section of the mold apparatus, a portion in the cavity 4 where the distribution of utilities is uneven, for example, Individual utility openings are provided at the distal ends of the second cavities 41, 42 having a bag-shaped cross section formed on the inner surfaces of the dies 51, 61, and passages communicating with external utility pipes are provided in the openings. In that the pipes 41a and 42a are provided.

In this case, the pipe 41a on the convex mold 61 side is
It is connected to the internal pipe 72a extending from the slit 7a and communicates with the external use port 73a. However, the pipe 42a on the concave mold 51 side is newly provided from the tip of the second cavity 42. It is provided so as to communicate with the external service opening 43a.

According to the present invention, the cavity 4
In each of the parts where the distribution of utilities is uneven, passages communicating with the external utility pipes are individually formed, so that steam can be supplied and compressed as necessary using these passages. Utility operations such as air supply, exhaust for vacuum depressurization, or pressure adjustment in the cavity and drainage can be performed individually in the same manner as in the case of the slit first. Uniformity can be eliminated.

In such a foam molding die apparatus of the present invention, as can be easily understood from the structure, the pre-foamed raw material beads described above are filled in the cavity, and then the pressure is reduced and exhausted. From, heating with steam for heating,
In the foam molding method of foaming, fusing, cooling and solidifying, and taking out as a foam molded body made of a predetermined foamed polystyrene resin or the like, using the slit and utility opening in place of the conventional vent hole, This can be done as described.

For example, when evacuating under reduced pressure, the slit 7
a to utility port 73a, and slit 7b to utility port 73b
After depressurizing and exhausting from one or both of them to directly reduce the pressure in the cavity 4, the steam for preheating may be directly supplied in the same manner. At this time, if necessary, the piping 41a,
The unevenness of the second cavities 41 and 42 may be eliminated by using 42a.

At the time of heating and fusing, similarly, steam at the fusing temperature may be directly supplied to the raw material beads in the chamber from one or both of the slits 7a and 7b. Utilizing this, it is possible to supply this to the second cavities 41 and 42 to heat this part where heat is difficult to reach by steam from the slits 7a and 7b. In this case, if necessary, another office 5
Needless to say, the required steam can be supplied from the chambers 4 and 64 to the chambers 5 and 6 to heat the entire molds 51 and 61 from the back.

In such a case, in order to prevent the slits 7a and 7b or the utility opening from being clogged by the raw material beads, the opening width on the cavity side is set as follows.
2.0 to 8 mmφ, which is the outer diameter of the raw material beads to be filled
In order to improve the finish of the foam molded article with less protrusion and burrs, it is preferable to make the gap as narrow as possible, but on the other hand, the passage resistance of the utility is small. It is preferable that the opening width is 0.1
It is appropriate to set it to 1.5 mm.

Next, another embodiment of the foam molding die apparatus of the first invention will be described with reference to FIG. 3 showing the upper half of the mold apparatus of this embodiment. A characteristic feature of the mold apparatus of this embodiment is that when the molds 51 and 61 are closed, the external use opening provided on the frame 23 side from the slit 7 a provided on the outer peripheral end portion of the cavity 4. 4
7a, an inter-model passage 45a, an inter-model cavity 46a
Are the mold outer peripheral parts 51a, 61a and the frames 23, 3
It is located at the 3rd seam.

In this case, a passage communicating with an external utility pipe from an individual utility opening provided at the tip of the second cavity 41, 42 having a bag-shaped cross section of the molds 51, 61. Are connected to the inter-cavity 46a, and a common external use opening 47a
It is supposed to communicate with. Of course, it goes without saying that they may be made independent as shown in FIG.

In this case, a series of structures such as the inter-model passage 45a, the inter-model cavity 46a, and the external use opening 47a shown in FIG. It can appear symmetrically. Further, the external use opening 47 a may be provided on the side of the frame 33 instead of the frame 23.

According to this embodiment, as the inter-mold cavity 46a, a conventionally existing one can be used, and the inter-mold passage 45a extends over the entire periphery of the front end portion of the outer periphery of the cavity 4. It may be formed in a belt shape or may be formed intermittently. Various utility pipes are connected to the external utility port 47a communicating with the inter-cavity 46a in the same manner as the external utility ports 73a and 43a of FIG. 2, and the same utility operations as described above are separately and independently performed. You can do it.

Further, in this embodiment, in addition to the advantages described above, when heating or cooling at the time of foam molding, the periphery of the mold passage 45a and the mold cavity 46a which are portions of the mold having a relatively large heat capacity. Since the part can be efficiently heated or cooled, a remarkable advantage that the molding operation time can be shortened is also obtained.

Next, an embodiment of a foam molding die apparatus according to the second invention will be described with reference to FIG. In FIG. 4, in a pair of combination molds formed in a state surrounding a cavity for forming a foamed molded body, slits exposed in the cavity are arranged along joint portions of the combination molds, The slit is provided with a passage communicating with an external utility pipe as in the case described above.

The feature of this embodiment is that a pair of slits 7a and 7b is provided at the position of the outer peripheral end opposite to the cavity 4 and the interval between the slits is 100 mm or more. In the case of (1), individual utility openings 81 (two openings are shown in FIG. 4) in the mold surface (the surface of the convex mold in FIG. 4) at an intermediate position between the pair of slits 7a and 7b. And slits 7a, 7a
The installation location and the number of the utility openings 81 are set so that the distance between the b and the utility openings 81 is 100 mm or less, and the inter-mold cavity portion 46 communicating with the external utility pipe is set in the openings 81.
The point is that a pipe 81a is provided as a passage connecting to b.

Although the shape of the utility opening 81 is not particularly limited, a point-like shape similar to a conventional core vent or a slit-like shape having a certain length can be employed. In any case, in order to prevent the openings from being clogged by the raw material beads, it is necessary to set the opening width on the cavity side to be equal to or less than the outer diameter of the raw material beads to be filled.

As described above, according to the second embodiment of the present invention, the pair of slits 7a and 7b are opposed to each other with the cavity 4 interposed therebetween. For this purpose, utility operations that can supply utilities such as steam can be adopted.In particular, the operation of replacing the air between the raw material beads filled in the cavity with steam and the operation of heating the raw material beads are quick. This is advantageous because advantages such as being able to be performed are obtained.

Further, since a required number of utility openings 81 are provided at intervals of a maximum of 100 mm, the distribution of utilities is smooth so that the distribution of utilities in the cavity is not biased or the speed is uneven. There are advantages that can be supplemented. For this reason, even when the central flat portion of the cavity 4 has a shape that is long compared to the thickness, for example, when the length / thickness ratio is 20 or more, the density unevenness of the central flat portion, the uneven foaming, etc. Can be suppressed.

[0032]

The foam molding die apparatus of the present invention is constructed as described above, so that the vent hole which was conventionally required can be omitted, but 1) the mold material cost is reduced. It becomes cheaper, and the manufacturing and processing cost of the mold can be reduced. 2) No special maintenance is required. 3) The thermal efficiency of heating and cooling is improved, which is effective for energy saving and shortening of cycle time. 4) The drying step can be omitted because the water content of the molded body is reduced. 5) The surface of the molded article is smooth and has excellent appearance quality. 6) There is an effect that the degree of freedom of the utility operation is expanded, and the utility operation can be performed in a finer manner.

Furthermore, there is a special effect of preventing uneven packing density of the raw material beads, uneven heating and cooling, and the like in the cavity portion where utilities such as compressed air do not easily flow. Therefore, the present invention has a very large industrial value as a foam molding die apparatus which has solved the conventional problems.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part for describing an embodiment of the present invention.

FIG. 2 is a partially cutaway sectional view for explaining details of the embodiment.

FIG. 3 is a partially cutaway sectional view for explaining another embodiment of the present invention.

FIG. 4 is an essential part cross-sectional view for explaining an embodiment of the second invention.

FIG. 5 is a sectional view of an essential part for explaining a conventional foam molding die apparatus.

[Explanation of symbols]

4 cavity, 41, 42 second cavity, 41
a, 42a piping, 5 concave side chamber, 51 concave mold,
52 frame, 53 back plate, 54 upper service opening, 55
Lower port, 6 Convex side chamber, 61 Convex mold, 6
2 frame, 63 back plate, 64 upper office, 65
Lower door, 7a, 7b slit, 73a, 73b
Service entrance, 71a, 71b Inter-model passage, 72a, 72b
Internal piping.

Claims (4)

[Claims] 1. A pair of combined dies formed so as to surround a cavity for forming a foamed molded product, a slit exposed in the cavity is provided along a joint portion of the combined mold. The slit is provided with a passage communicating with an external utility pipe, and an individual utility opening is provided in a portion where the distribution of utility is uneven in the cavity. And a passage communicating with the utility pipe of (1). 2. An individual utility opening is disposed at the tip of a second cavity having a bag-shaped cross section formed on the inner surface of the mold, and a passage communicating with an external utility pipe is provided in the opening. The mold apparatus for foam molding according to claim 1, further comprising: 3. A pair of combined molds formed so as to surround a cavity for forming a foamed molded body, wherein the pair of combined molds are opposed to each other across the cavity along a joint portion of the combined mold. A pair of slits exposed in the cavity are provided, and each slit is provided with a passage communicating with an external utility pipe, and when the interval between the slits is 100 mm or more, a metal at an intermediate position between the slits is provided. A mold apparatus for foam molding, wherein a separate utility opening is provided on a mold surface, and a passage communicating with an external utility pipe is provided in the opening. 4. The foam molding metal according to claim 1, wherein an opening width of the slit on the cavity side and an opening width of the utility opening are formed to be smaller than an outer diameter of the raw material beads to be filled. Mold device.