JP2013099882A - Method for molding molded foam product and molded foam product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molded foam product which can readily fit another member in a fitting part.SOLUTION: The molded foam product (100) has the fitting part (104a) for another member to be fitted in. Foaming magnification of the fitting part (104a) is higher than one of a body portion (102) of the molded foam product (100).

Description

  The present invention relates to a method for molding a foam molded article and a foam molded article.

  A conventional method for forming a foamed molded article is to form a cylindrical foamed parison by extruding a foamed molten resin obtained by melting and kneading a base resin and a foaming agent from a die, and sandwiching the foamed parison with a split mold. Was blown by injecting a pressurized gas into the inside thereof to form a hollow foamed molded body (see, for example, Japanese Patent Laid-Open No. 63-309434).

  In addition, since the outer diameter of the foaming molded object shape | molded with the shaping | molding method mentioned above is controlled by the inner wall face (cavity surface) of a division mold, it can finish to a predetermined dimension. However, since the inner diameter of the foamed molded body is only restricted by the pressing force of the pressurized gas blown into the inside of the foam parison, it is difficult to finish to a predetermined dimension. For this reason, the foam molded body molded by the above-described molding method is likely to have a variation in thickness, which causes a problem when other members such as a register are fitted into the foam molded body.

  For example, when the inner diameter of the fitting portion into which the other member is fitted is larger than the outer diameter of the other member, a gap is generated between the fitting portion and the other member, and air leaks from the fitting portion, Other members may easily come off. Moreover, when the internal diameter of a fitting part becomes smaller than the outer diameter of another member, it will become difficult to fit another member to a fitting part. In particular, the parting line portion is prone to the occurrence of double-thickness, so that the resin swells on the inside of the foamed molded product, and the inner diameter of the fitting portion may not be a predetermined dimension.

  For this reason, it is necessary to regulate the inner diameter of the fitting portion into which the other member is fitted and finish it to a predetermined dimension with high accuracy.

  Patent Document 2 (Japanese Patent No. 4087209) discloses a method for regulating the inner diameter of a foamed molded product.

  In Patent Document 2, as shown in FIG. 9 (a), the foam parison 11 pushed out from the die 21 is disposed in the molds 22a and 22b, and the fitting portion forming gold is placed in the foam parison 11 from below. A mold 32 including a mold 31c and a mold 31d is inserted.

  Next, as shown in FIG. 9B, the foam parison 11 is sandwiched between the mold 22a and the mold 22b, and the molds 22a and 22b are closed while gas is blown into the foam parison 11. At this time, a portion sandwiched between the recesses 33a, 33b and the mold 31c is formed as a convex fitting portion, and a portion sandwiched between the straight portions 34a, 34b and the mold 31d is formed as a concave fitting portion. It is formed.

  Next, the molds 22a and 22b are opened, the foam molded body is taken out, unnecessary burrs are removed, and the convex fitting portion 4a and the concave fitting portion having a vertical cross section as shown in FIG. 4b is formed.

JP-A 63-309434 Japanese Patent No. 4087209

  In Patent Document 2, an inner diameter of the foam parison 11 is regulated by inserting a mold 32 including a mold 31c and a mold 31d for forming a fitting portion into the foam parison 11.

  However, in Patent Document 2, the portion sandwiched between the recesses 33a and 33b and the mold 31c is compressed to form the convex fitting portion 4a, and the straight portions 34a and 34b and the mold 31d Since the sandwiched portion is compressed to form the concave fitting portion 4b, the expansion ratio of the fitting portions 4a, 4b is lower than other portions (duct body portion, etc.), and the fitting portions 4a, 4b, 4b becomes hard. As a result, it becomes difficult to fit other members into the fitting portions 4a and 4b.

  This invention is made | formed in view of the said situation, and it aims at providing the shaping | molding method of a foaming molding and a foaming molding which can fit another member easily in a fitting part.

  In order to achieve this object, the present invention has the following features.

<Method of forming foam molded article>
The molding method of the foamed molded product according to the present invention is:
A molding method in which a foamed molded article is formed by sandwiching a foamed molten resin with a split mold,
A step of disposing an inner diameter regulating member for regulating an inner diameter of the foam molded body between the split molds;
Without compressing at least a part of the foamed molten resin disposed between the split mold and the inner diameter regulating member, the foamed molten resin was sandwiched between the split molds and sandwiched between the split molds. The foamed molded body is molded from the foamed molten resin, and the foamed molten resin disposed between the split mold and the inner diameter regulating member is sucked by a suction portion provided in the inner diameter regulating member and the foamed And a step of forming a fitting portion for fitting another member into the molded body.

<Foamed molded product>
The foamed molded product according to the present invention is
A foamed molded article having a fitting portion for fitting another member,
The expansion ratio of the fitting portion is higher than that of the main body portion of the foam molded body.

  According to the present invention, the other member can be easily fitted into the fitting portion.

It is a perspective view which shows the duct 100 as a foaming molding of this embodiment, (a) is a front view of the duct 100, (b) is sectional drawing (fitting part) which follows the AA line of (a) (C) is a cross-sectional view taken along line BB of (a) (cross-sectional view of the duct body 102). 3 is a diagram showing an example of a method for forming a duct 100. FIG. FIG. 7 is a diagram illustrating a configuration example around the inner diameter regulating member 32, (a) is a side sectional view of the inner diameter regulating member 32, and (b) is a sectional view taken along line AA in (a). It is a 1st figure which shows the example of formation of the fitting part 104a. It is a 2nd figure which shows the example of formation of the fitting part 104a. 3 is a diagram illustrating a configuration example of a suction unit 42. FIG. It is a figure which shows the example of a shaping | molding method of the duct 100 of 2nd Embodiment. 5 is a diagram illustrating an example of a method for arranging an inner diameter regulating member 32. FIG. It is a figure which shows the example of a shaping | molding method of the conventional foaming molding.

<Outline of Foam Molded Body 100 of the Present Embodiment>
First, the outline | summary of the foaming molding 100 of this embodiment is demonstrated, referring FIGS. 1-3.

  As shown in FIG. 1, the foam molded body 100 of the present embodiment is a foam molded body 100 having a fitting portion 104a for fitting another member (not shown), and the expansion ratio of the fitting portion 104a is as follows. It is characterized by being higher than the main body portion 102 of the foam molded body 100.

  In the foam molded body 100 of the present embodiment, for example, as shown in FIG. 2A, an inner diameter regulating member 32 that regulates the inner diameter of the foam molded body 100 is disposed between the divided molds 22a and 22b. Then, as shown in FIG. 2B, the divided molds 22a, 22b are formed without compressing at least a part of the foamed molten resin 11 disposed between the divided molds 22a, 22b and the inner diameter regulating member 32. The foamed molten resin 11 is sandwiched between and the foamed molded resin 100 is molded with the foamed molten resin 11 sandwiched between the divided molds 22a and 22b, and is disposed between the divided molds 22a and 22b and the inner diameter regulating member 32. The foamed molten resin 11 is sucked by a suction portion (42: see FIG. 3) provided on the inner diameter regulating member 32 to form a fitting portion 104a. Thereby, the foaming molding 100 which has the fitting part 104a shown in FIG. 1 is obtained.

  The foam molded body 100 of the present embodiment molds the foam molded body 100 without compressing at least a part of the foamed molten resin 11 disposed between the split molds 22a and 22b and the inner diameter regulating member 32. Since the foamed molten resin 11 is sucked by the suction portion 42 provided on the inner diameter regulating member 32 to form the fitting portion 104a, the expansion ratio of the fitting portion 104a is larger than that of the main body portion 102 of the foam molded body 100. Is also high. As a result, the fitting portion 104a is easily deformed, and other members can be easily fitted into the fitting portion 104a. Hereinafter, with reference to the attached drawings, the foamed molded product and the molding method of the present embodiment will be described in detail. In the following embodiments, a duct that is an example of a foam molded body will be described in detail. The present invention is not limited to ducts, and can be applied to other foamed molded articles such as other automobile parts and containers.

(First embodiment)
<Configuration example of duct 100>
First, the duct 100 of this embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating a configuration example of the duct 100, FIG. 1A is a configuration diagram of the duct 100, and FIG. 1B is a cross-sectional view taken along the line AA in FIG. FIG. 1C is a cross-sectional view taken along line BB in FIG. 1A (cross-sectional view of the duct main body 102).

  The duct 100 of this embodiment includes a duct main body 102 and a concave fitting portion 104a. The inside of the duct 100 of the present embodiment has a hollow space (hollow part) 103. Further, parting lines L1, L2 are formed on the wall surface of the duct 100. Note that the configuration of the duct 100 illustrated in FIG. 1 is an example, and is not limited to the configuration illustrated in FIG. 1.

  The cross section shown in FIGS. 1B and 1C is a cross section perpendicular to the hollow extending direction of the duct 100 (the direction indicated by the arrow Z in FIG. 1), and FIG. 1B shows the fitting portion 104a. FIG. 1C shows a cross section of the duct body 102. In the duct 100 of the present embodiment, the expansion ratio of the fitting portion 104a shown in FIG. 1 (b) is higher than that of the duct main body 102 shown in FIG. 1 (c). The hollow extending direction is a direction in which the hollow portion 103 extends in the duct 100. When both ends are open like the duct 100 of the present embodiment, this hollow extending direction means a direction parallel to the ventilation path in the duct 100.

  The duct 100 of the present embodiment is made of a foamed molten resin obtained by melting and kneading a base resin mainly composed of a polyolefin resin and a foaming agent.

  As the polyolefin-based resin, high-density polyethylene resin, low-density polyethylene resin, polyethylene-based resin such as linear low-density polyethylene resin, polypropylene-based resin, and the like are applicable. In addition, polyolefin resin shall contain what copolymerized the olefin component and other components, such as styrene. As the polyolefin resin, it is particularly preferable to use a polypropylene resin excellent in mechanical properties such as heat resistance and rigidity.

  Examples of the foaming agent include inorganic physical foaming agents such as air, carbon dioxide, nitrogen gas and water, and organic physical foaming agents such as butane, pentane, hexane, dichloromethane and dichloroethane, or sodium bicarbonate, citric acid, citric acid. Chemical foaming agents such as sodium acid and azodicarbonamide are applicable. Furthermore, these physical foaming agents and chemical foaming agents can be used in combination.

  The duct 100 of the present embodiment can be molded in a range where the expansion ratio of the duct body 102 is, for example, 1.5 to 6.0 times. In the duct 100 of the present embodiment, the expansion ratio of the fitting portion 104a is higher than that of the duct main body 102 by about 0.1 times or more.

The expansion ratio was calculated as follows.
Test pieces were cut at 2 cm square from a total of three locations in the center of the duct body 102 and near both ends (excluding the fitting portion 104a). The specific gravity of the three test pieces was measured with an electronic specific gravity meter EW-200SG manufactured by Alpha Mirage Co., Ltd. according to JIS K-7112. The average specific gravity of the duct body 102 was calculated by arithmetically averaging the three specific gravity values. Then, the expansion ratio was calculated by dividing the specific gravity of the polyolefin resin before foaming by the average specific gravity.
The expansion ratio of the fitting portion 104a was also calculated in the same manner as described above.

  If the expansion ratio of the duct main body 102 is less than 1.5 times, there is a disadvantage that sufficient weight reduction cannot be achieved and condensation is likely to occur on the surface. In particular, the duct 100 for a vehicle has a drawback that the heat loss performance is poor when the expansion ratio is less than 1.5 times. On the other hand, when the expansion ratio exceeds 6.0 times, it is easily deformed by an external force.

The average thickness of the duct body 102 of the present embodiment is preferably 0.7 to 4.0 mm. The average thickness of the fitting portion 104a is about 0.2 mm or more thicker than that of the duct body 102.
The average wall thickness was calculated as follows.
In the cross section of the three places in the center of the duct body 102 and in the vicinity of both ends (excluding the fitting portion 104a), the portions that intersect with the perpendicular bisector of the straight line connecting the two mold dividing points (total 6 The wall thickness was measured with calipers. And the average value of six measured values was computed as average thickness.
The average thickness of the fitting portion 104a was calculated in the same manner as described above.
When the average thickness of the duct body 102 is less than 0.7 mm, the strength is weak and the duct body 102 is easily deformed by an external force. On the other hand, if the average wall thickness exceeds 4.0 mm, the thickness variation tends to increase in a duct with a high expansion ratio of 2.5 times or more, and the pressure loss when the wind flows will increase.

<Example of molding method of duct 100>
Next, an example of a method for forming the duct 100 of the present embodiment will be described with reference to FIG. FIG. 2 is a view showing a configuration example around the split molds 22a and 22b of the molding apparatus for molding the duct 100 of the present embodiment.

  First, a base resin for forming the duct 100 is melt-kneaded in an extruder (not shown), a foaming agent is injected, and then extruded from the die 21 as shown in FIG. A foamed cylindrical foam parison 11 is formed, and the foam parison 11 is placed in the divided molds 22a and 22b. Further, from the lower side of the foam parison 11, an inner diameter regulating member 32 having a fitting portion forming die 31d is inserted into the foam parison 11.

  The molding apparatus according to the present embodiment includes a concave fitting formation portion 34a provided at a lower portion in the molding space of the split mold 22a and a concave fitting formation portion 34b provided at a lower portion in the molding space of the split mold 22b. Then, the concave fitting portion 104a is formed using the mold 31d.

  For this reason, the inner diameter regulating member 32 is inserted so that the mold 31d inserted into the foamed parison 11 is positioned between the concave fitting formation portions 34a and 34b.

  Next, as shown in FIG. 2 (b), the split molds 22a and 22b are closed, the foam parison 11 is sandwiched between the split molds 22a and 22b, and a gas is blown into the foam parison 11 to form the hollow portion 103. A duct 100 having

  When the split molds 22a and 22b are closed, the molding apparatus of this embodiment has at least a part of the foam parison 11 sandwiched between the concave fitting formation portions 34a and 34b and the mold 31d as shown in FIG. Is not compressed, a partial distance T1 between the inner peripheral shape of the concave fitting formation portions 34a, 34b and the outer peripheral shape of the mold 31d when the split molds 22a, 22b are closed (FIG. 3 (b )) Is equal to or greater than the layer thickness T2 of the foam parison 11 (see FIG. 3B), and is formed around the foam parison 11 sandwiched between the concave fitting formation portions 34a and 34b and the mold 31d. A gap 40 is formed. However, the distance T1 between the inner peripheral shape of the concave fitting formation portions 34a and 34b and the outer peripheral shape of the mold 31d needs to be configured to be equal to or greater than the layer thickness T2 of the foam parison 11 in all portions. However, it may be configured such that there is a portion where at least a part of the foam parison 11 is not compressed. FIG. 3A shows an enlarged view around the mold 31d constituting the inner diameter regulating member 32, and FIG. 3B shows a cross-sectional view taken along line AA shown in FIG.

  In the molding apparatus of the present embodiment, a blowing part 41 for blowing gas into the inside of the foam parison 11 is provided in the mold 31d of the inner diameter regulating member 32, and gas (air) is introduced into the inside of the foam parison 11 via the blowing part 41. ).

  The molding apparatus of the present embodiment forms a gap 40 (see FIG. 3 (b)) so as not to compress as much as possible the portion of the foam parison 11 sandwiched between the concave fitting formation portions 34a, 34b and the mold 31d. Therefore, the gas blown into the inside of the foam parison 11 from the blow part 41 easily flows out of the foam parison 11 through the gap 40. For this reason, in the molding apparatus of the present embodiment, the foam parison 11 is brought into contact with the mold 31d at the cut-off portion 43 formed on the entire circumference of the concave fitting formation portions 34a and 34b, and blown into the foam parison 11 Gas is prevented from leaking outside the foamed parison 11. As a result, when the split molds 22a and 22b are closed, the foam parison 11 is stretched and deformed in the split molds 22a and 22b by the gas blown into the foam parison 11, and the split mold 22a , 22b, and the duct 100 having the hollow portion 103 inside the duct 100 can be formed.

  In the molding apparatus of this embodiment, as shown in FIG. 2, the split molds 22a and 22b are provided with a decompression pipe 23, and the decompression pipe 23 is used to decompress the split molds 22a and 22b. Thus, the outer surface of the foam parison 11 and the cavities 24 of the divided molds 22a and 22b are brought into close contact with each other. As a result, the surface shape of the cavity 24 of the divided molds 22a and 22b can be reflected in the duct body 102.

  Next, a gas is sucked from the suction portion 42 provided in the mold 31d of the inner diameter regulating member 32, and as shown in FIG. 4, the foam parison sandwiched between the concave fitting formation portions 34a and 34b and the mold 31d. The portion 11 is brought into close contact with the surface of the mold 31d, and the foamed parison 11 is secondarily foamed to form a concave fitting portion 104a having a higher expansion ratio than the portion of the duct body 102. The molding apparatus of the present embodiment has a concave shape because the inner peripheral shape of the concave fitting formation portions 34a, 34b when the split molds 22a, 22b are closed is different from the outer peripheral shape of the die 31d of the inner diameter regulating member 32. The inner peripheral shape and the outer peripheral shape of the concave fitting portion 104a formed by the portion of the foam parison 11 sandwiched between the fitting forming portions 34a and 34b and the mold 31d can be made different. The gas sucked by the suction unit 42 is sent to a vacuum pump (not shown).

  Next, the split molds 22a and 22b are opened, and the duct 100 shown in FIG. In the molding apparatus of the present embodiment, the cutout portion 43 is formed on the entire circumference of the concave fitting formation portions 34a and 34b. Therefore, the fitting portion 104a is cut by the cutout portion 43, and FIG. The duct 100 having the fitting portion 104a shown in FIG. Next, unnecessary burrs are removed from the duct 100 shown in FIG. 2C taken out from the divided molds 22a and 22b, and the upper end of the duct 100 is cut with a cutter or the like. Thereby, the duct 100 having the concave fitting portion 104a as shown in FIG. 1 can be formed.

  In FIG. 2, the suction path of the decompression pipe 23 and the like is schematically shown. However, a suction hole for sucking the foam parison 11 substantially uniformly is formed on the entire cavity surfaces of the divided molds 22a and 22b. Can do. In the molding apparatus of the present embodiment, it is preferable to suck the foam parison 11 by providing a suction hole in the cavity surface of the portion forming the fitting portion 104a. As a result, the foam parison 11 can be prevented from leaving the cavity when the foam parison 11 is sucked by the suction portion 42 provided in the mold 31d of the inner diameter regulating member 32, so that the outer shape of the fitting portion 104a is accurately formed. can do.

  In the above embodiment, the inner diameter regulating member 32 is inserted into the foamed parison 11 after the foamed parison 11 is disposed in the divided molds 22a and 22b. However, after the inner diameter regulating member 32 is arranged in advance in the divided molds 22a and 22b, the foam parison 11 is arranged in the divided molds 22a and 22b so that the inner diameter regulating member 32 is positioned in the foamed parison 11. It is also possible to do. That is, as long as the inner diameter regulating member 32 can be disposed in the foam parison 11, the order of the steps is not particularly limited, and can be performed in any order.

  Moreover, in the said embodiment, as shown to FIG. 3, FIG. 4, the inner peripheral shape of the concave fitting formation parts 34a and 34b when the division molds 22a and 22b are closed is made into a square shape, The outer peripheral shape of the mold 31d was elliptical. However, the inner peripheral shape of the concave fitting formation portions 34a and 34b when the split molds 22a and 22b are closed and the outer peripheral shape of the mold 31d of the inner diameter regulating member 32 are the shapes shown in FIGS. However, it is possible to make each of any shape. For example, as shown in FIG. 5, the inner peripheral shape of the concave fitting formation portions 34a, 34b when the divided molds 22a, 22b are closed is an elliptical shape, and the outer peripheral shape of the mold 31d of the inner diameter regulating member 32 is a square shape. It can also be shaped. FIG. 5A shows a state before the foamed parison 11 is sucked by the suction part 42, and FIG. 5B shows a state after the foamed parison 11 is sucked by the suction part 42. The inner peripheral shape of the concave fitting formation portions 34a and 34b when the divided molds 22a and 22b are closed and the outer peripheral shape of the mold 31d of the inner diameter regulating member 32 can be the same shape. .

  Moreover, in the said embodiment, it decided to shape | mold the duct 100 using blow molding and vacuum forming together. However, it is also possible to form the duct 100 using only blow molding, or to form the duct 100 using only vacuum molding. In the case of using blow molding, in order to prevent the gas blown into the foam parison 11 from leaking to the outside of the foam parison 11, the cut-off portion 43 formed on the entire circumference of the concave fitting formation portions 34a and 34b. It is necessary to configure so as to prevent the outflow of gas. However, when forming the duct 100 using only vacuum forming, it is not necessary to blow gas into the foam parison 11, so in this case, the cut-off portion 43 is formed in the concave fitting formation portions 34a and 34b. It is not necessary. However, when there is no cut-off portion 43, it is necessary to cut the fitting portion 104a with a cutter or the like after taking out the duct 100 from the divided molds 22a and 22b. In the above embodiment, the blowing portion 41 is provided in the mold 31d of the inner diameter regulating member 32, and the gas is blown into the foam parison 11. However, the blow part 41 may not be provided in the mold 31d, and a blow pin may be inserted into the foam parison 11 and gas may be blown into the foam parison 11.

  Moreover, in the said embodiment, as shown to Fig.3 (a), gas is attracted | sucked from the suction part 42 provided in the metal mold | die 31d of the internal diameter control member 32, and the concave fitting formation parts 34a and 34b and the metal mold | die 31d are attracted | sucked. The part of the foamed parison 11 sandwiched between the two parts was brought into close contact with the surface of the mold 31d, and the foamed parison 11 was subjected to secondary foaming to form a concave fitting part 104a having a higher foaming ratio than the part of the duct main body 102. However, the structure of the suction part 42 is not limited to the structure shown in FIG. 3. For example, as shown in FIG. 6, innumerable small holes 42 a connected to the suction part 42 on the surface in contact with the foam parison 11. It is also possible to uniformly suck the foam parison 11 of the portion constituting the fitting portion 104a using the small hole 42a. When the part of the fitting part 104a becomes long, the shape of the suction part 42 shown in FIG. 3 can suck only a part of the foam parison 11 constituting the fitting part 104a. Since the foam parison 11 can be sucked uniformly by providing the innumerable small holes 42a, the foaming magnification of the portion constituting the fitting portion 104a can be made uniform. In the above embodiment, the suction portion 42 is provided in the mold 31d. However, the suction fitting portion 34a, 34b is also provided with the suction portion 42, and the suction fitting 42 provided in the die 31d and the concave fitting formation portion. It is also possible to suck both surfaces of the foamed parison 11 with the suction portions provided in 34a and 34b.

  Moreover, in the said embodiment, it comprised so that the outflow of gas might be prevented with the cut-off part 43 formed in the perimeter of the concave fitting formation parts 34a and 34b. However, if it is possible to prevent the outflow of gas, a compression portion (not shown) is formed instead of the cutout portion 43, and the foam parison 11 is compressed by the compression portion so as to prevent the outflow of gas. It is also possible to configure. In addition, when forming the compression part instead of the cut-off part 43, the compression part is formed below the position of the cut-off part 43, and a portion where the foam parison 11 is compressed by the compression part is formed, and the compression part It is possible to prevent the portion constituting the concave fitting portion 104a from being compressed. It is also possible to form a compression portion above the position of the cutout portion 43 and leave the portion where the foam parison 11 is compressed in the compression portion in the fitting portion 104a. However, when leaving the compressed part of the foam parison 11 in the fitting part 104a, it is necessary to leave it only in a part of the fitting part 104a in order to make the expansion ratio of the fitting part 104a higher than that of the duct body 102. There is.

<Operation / Effect of Duct 100 of this Embodiment>
Thus, in the present embodiment, the inner diameter regulating member 32 that regulates the inner diameter of the duct 100 is disposed between the divided molds 22a and 22b, and is disposed between the divided molds 22a and 22b and the inner diameter regulating member 32. Without compressing at least a part of the foamed parison 11, the foamed parison 11 is sandwiched between the split molds 22a and 22b, and the duct 100 is molded with the foamed parison 11 sandwiched between the split molds 22a and 22b and split. The foam parison 11 disposed between the molds 22a, 22b and the inner diameter regulating member 32 is sucked by the suction portion 42 provided on the inner diameter regulating member 32 to form the fitting portion 104a, and more than the portion of the duct body 102. A duct 100 having a fitting portion 104a with a high expansion ratio and a regulated inner diameter is formed. As a result, it is possible to obtain the duct 100 in which other members can be easily fitted into the fitting portion 104a while restricting the inner diameter of the fitting portion 104a.

  In the molding apparatus of the present embodiment, the inner diameter regulating member 32 is formed after the outer surface of the foam parison 11 and the inner peripheral shape of the concave fitting formation portions 34a and 34b provided in the divided molds 22a and 22b are brought into close contact with each other. The foam parison 11 is sucked from the suction part 42 provided in the mold 31d, and the inner surface of the foam parison 11 and the outer peripheral shape of the mold 31d are brought into close contact with each other. For this reason, as shown in FIGS. 4 and 5, a duct 100 in which the outer peripheral shape and the inner peripheral shape of the fitting portion 104a are different can be formed.

(Second Embodiment)
Next, a second embodiment will be described.

  In the first embodiment, as shown in FIG. 2, the duct 100 is formed using a cylindrical foamed parison 11 formed by extruding a foamed molten resin into a cylindrical shape. In the second embodiment, as shown in FIG. 7, the duct 100 is formed using a sheet-shaped foamed parison P formed by extruding a foamed molten resin into a sheet. Also in this case, by using the inner diameter regulating member 32 similar to that in the first embodiment, the fitting portion 104a similar to that in the first embodiment can be formed. However, in this embodiment, since the sheet-like foam parison P is used, the inner diameter regulating member 32 can be easily placed in the foam parison P as compared with the case where the cylindrical foam parison 11 is used as in the first embodiment. The fitting portion 104a can be formed in addition to the end portion of the duct 100.

  In the first embodiment, since the cylindrical foam parison 11 is used, it is necessary to insert the inner diameter regulating member 32 into the foam parison 11 from below the foam parison 11 as shown in FIG. Further, the fitting portion 104a can be formed only at the end of the duct 100.

  On the other hand, in this embodiment, since the sheet-like foam parison P is used, as shown in FIG. 7, the inner diameter regulating member 32 is not only below the foam parison P but also as shown in FIG. Moreover, it can be inserted into the foam parison P even from the side of the foam parison P. As a result, as shown in FIG. 8B, the fitting portion 104a can be formed on the side other than the end portion of the duct 100. Even when the fitting portion 104a is formed on the side other than the end portion of the duct 100, the expansion ratio of the fitting portion 104a can be made larger than that of the duct main body 102.

<Operation / Effect of Duct 100 of this Embodiment>
In this manner, by forming the duct 100 using the sheet-like foam parison P, the inner diameter regulating member 32 can be easily inserted into the foam parison P, and the fitting portion 104a is formed at an arbitrary location. can do.

  The above-described embodiment is a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiment alone, and various modifications are made without departing from the gist of the present invention. Implementation is possible.

  For example, in the above-described embodiment, since the curved duct 100 is formed, the fitting portion 104a is formed using the inner diameter regulating member 32 only on the lower end side of the duct 100. However, in the case of a straight duct 1 like the duct 1 shown in FIG. 9, the fitting portion 104a of the present embodiment described above can be formed also on the upper end side of the duct 1 using the inner diameter regulating member 32. .

  In the above-described embodiment, the duct 100 having the fitting portion 104a is formed using the inner diameter regulating member 32. However, the fitting portion 104a is not fitted into another member, and can also be used as an opening for allowing gas to flow into the duct 100 or gas to flow out of the duct 100. Since the fitting portion 104a of the present embodiment has a higher foaming ratio than the duct body 102, condensation is unlikely to occur on the surface. For this reason, by using the fitting portion 104a described above as an opening, it is possible to configure an opening where condensation is unlikely to occur.

DESCRIPTION OF SYMBOLS 100 Duct 102 Duct main body 103 Hollow part 104a Fitting part L1, L2 Parting line 21 Die 11 Foam parison (cylindrical shape)
22a, 22b Split mold 23 Pressure reducing pipe 24 Cavity 31d Mold 32 Inner diameter regulating member 34a, 34b Concave fitting formation part 40 Gap 41 Blow part 42 Suction part 42a Small hole 43 Cutout part P Parison (sheet-like)
51 T die

Claims (5)

A molding method in which a foamed molded article is formed by sandwiching a foamed molten resin with a split mold,
A step of disposing an inner diameter regulating member for regulating an inner diameter of the foam molded body between the split molds;
Without compressing at least a part of the foamed molten resin disposed between the split mold and the inner diameter regulating member, the foamed molten resin was sandwiched between the split molds and sandwiched between the split molds. The foamed molded body is molded from the foamed molten resin, and the foamed molten resin disposed between the split mold and the inner diameter regulating member is sucked by a suction portion provided in the inner diameter regulating member and the foamed Forming a fitting portion for fitting another member into the molded body. The split mold has a fitting forming part that forms the fitting part,
The inner peripheral shape of the fitting forming portion in a state where the split mold is closed and the outer peripheral shape of the inner diameter regulating member constitute a different shape, and the gap is formed between the fitting forming portion and the inner diameter regulating member. The foamed molten resin disposed is formed into a shape along the inner peripheral shape of the fitting forming portion and the outer peripheral shape of the inner diameter regulating member, and the fitting has a different outer peripheral shape and inner peripheral shape. The molding method according to claim 1, wherein a joint portion is formed.   The molding method according to claim 1 or 2, wherein the foamed molded article is molded using the foamed molten resin extruded into a sheet shape. A foamed molded article having a fitting portion for fitting another member,
The foamed molded article is characterized in that the expansion ratio of the fitting portion is higher than that of the main body portion of the foamed molded article.   The foamed molded product according to claim 4, wherein an outer peripheral shape and an inner peripheral shape of the fitting portion are different.

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