JP7347081B2 - Manufacturing method and equipment for foamed resin molded products - Google Patents

Manufacturing method and equipment for foamed resin molded products Download PDF

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JP7347081B2
JP7347081B2 JP2019179427A JP2019179427A JP7347081B2 JP 7347081 B2 JP7347081 B2 JP 7347081B2 JP 2019179427 A JP2019179427 A JP 2019179427A JP 2019179427 A JP2019179427 A JP 2019179427A JP 7347081 B2 JP7347081 B2 JP 7347081B2
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圭介 東中川
満晴 金子
正明 大西
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Mazda Motor Corp
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Description

本発明は、発泡樹脂成形品の製造方法及び製造装置に関する。 The present invention relates to a method and apparatus for manufacturing a foamed resin molded article.

発泡樹脂成形品を成形する方法としてコアバック法が知られている。このコアバック法によれば、キャビティの容積が可変の金型に発泡剤を含む樹脂（以下、「発泡樹脂」という。）を充填する。金型に充填された発泡樹脂は、金型との接触面から冷却され、スキン層が形成される。その後、キャビティ内の発泡樹脂の温度が適当な温度になった状態でキャビティ内の容積が拡大され、これによりスキン層の内側に気泡構造のコア層が形成される。このようにして得られた発泡樹脂成形品は、エジェクタピンによって金型から押し出される。 A core-back method is known as a method for molding foamed resin molded products. According to this core-back method, a mold having a variable cavity volume is filled with a resin containing a foaming agent (hereinafter referred to as "foamed resin"). The foamed resin filled in the mold is cooled from the contact surface with the mold, forming a skin layer. Thereafter, when the temperature of the foamed resin within the cavity reaches an appropriate temperature, the volume within the cavity is expanded, thereby forming a core layer with a cellular structure inside the skin layer. The foamed resin molded product thus obtained is extruded from the mold by an ejector pin.

特開平５－４２６１０号Japanese Patent Application Publication No. 5-42610

コアバック法により成形された樹脂成形品は、一方の金型に設けたエジェクタピンによって金型から押し出される。このとき、エジェクタピンによって加えられた力はスキン層を介してコア層に伝達され、コア層の気泡が加圧される。その結果、気泡がエジェクタピンから加えられた力によって破裂したり、エジェクタピンで押された領域の発泡ガスが周辺に広がってスキン層をコア層から剥離したり、発泡樹脂成形品の表面が膨れて成形品の外観が損なわれるおそれがある。 A resin molded product molded by the core-back method is extruded from the mold by an ejector pin provided on one of the molds. At this time, the force applied by the ejector pin is transmitted to the core layer through the skin layer, and the bubbles in the core layer are pressurized. As a result, the bubbles may burst due to the force applied by the ejector pin, the foaming gas in the area pushed by the ejector pin may spread to the surrounding area, causing the skin layer to separate from the core layer, or the surface of the foamed resin molded product may swell. The appearance of the molded product may be damaged.

そこで、本発明は、発泡樹脂成形品を金型から取り出す際に生じ得る問題を解消し、優れた品質の外観を有する発泡樹脂成形品を製造できる製造装置及び製造方法を提供することを目的とする。 SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a manufacturing apparatus and a manufacturing method that can eliminate the problems that may occur when taking out a foamed resin molded product from a mold, and can manufacture a foamed resin molded product that has an appearance of excellent quality. do.

この目的を達成するために、本発明の実施形態に係る発泡樹脂成形品の製造方法は、第１の金型と第２の金型の分離面に形成されたキャビティに発泡樹脂を充填した後、前記キャビティの容積を大きくすることで前記発泡樹脂を発泡させる発泡樹脂成形品の製造方法であって、
前記キャビティに前記発泡樹脂を充填する工程（ａ）と、
前記第１の金型又は前記第２の金型の少なくとも一方を他方から遠ざけて前記キャビティの容積を大きくし、前記第１の金型に隣接する第１の発泡樹脂部分の連結気泡の割合を、前記第２の金型に隣接する第２の発泡樹脂部分の連結気泡の割合よりも大きく設定する工程（ｂ）と、
前記発泡樹脂成形品を前記第２の金型に残したまま前記第１の金型を前記発泡樹脂成形品から分離させる工程（ｃ）と、
前記発泡樹脂成形品を前記第２の金型から前記第１の金型に向かう方向に押して、前記発泡樹脂成形品を前記第２の金型から分離させる工程（ｄ）、を備えており、
前記工程（ｂ）は、予め、前記第１の金型に接する前記第１の発泡樹脂部分を前記第２の金型に接する前記第２の発泡樹脂部分よりも冷却し、前記第１の発泡樹脂部分の温度が前記第２の発泡樹脂部分よりも所定温度低い状態で行われ、
前記キャビティは、前記工程（ｂ）の開始前に第１の容積を有し、
前記工程（ｂ）は、
前記キャビティの容積を前記第１の容積から第２の容積まで増加させる第１工程（ｂ１）と、
前記キャビティの容積を前記第２の容積から第３の容積まで増加させる第２工程（ｂ２）と、
前記第１工程（ｂ１）と前記第２工程（ｂ２）の間にあって、前記キャビティの容積を前記第２の容積に維持する中間工程、を備えることを特徴とする。
In order to achieve this objective, the method for manufacturing a foamed resin molded product according to an embodiment of the present invention is such that after filling a cavity formed on the separation surface of a first mold and a second mold with foamed resin, , a method for producing a foamed resin molded product in which the foamed resin is foamed by increasing the volume of the cavity,
(a) filling the cavity with the foamed resin;
At least one of the first mold and the second mold is moved away from the other to increase the volume of the cavity, and the proportion of connected cells in the first foamed resin portion adjacent to the first mold is increased. , a step (b) of setting the proportion of connected cells to be larger than the proportion of connected cells in the second foamed resin portion adjacent to the second mold;
(c) separating the first mold from the foam resin molded product while leaving the foam resin molded product in the second mold;
a step (d) of pushing the foamed resin molded product in a direction from the second mold toward the first mold to separate the foamed resin molded product from the second mold ,
In the step (b), in advance, the first foamed resin portion in contact with the first mold is cooled lower than the second foamed resin portion in contact with the second mold, and the first foamed resin portion is cooled in advance. carried out in a state where the temperature of the resin part is a predetermined temperature lower than the second foamed resin part,
the cavity has a first volume before the start of step (b);
The step (b) includes:
a first step (b1) of increasing the volume of the cavity from the first volume to a second volume;
a second step (b2) of increasing the volume of the cavity from the second volume to a third volume;
The method is characterized by comprising an intermediate step between the first step (b1) and the second step (b2), in which the volume of the cavity is maintained at the second volume.

また、本発明の実施形態に係る発泡樹脂成形品の製造装置は、第１の金型と第２の金型の分離面に形成されたキャビティに発泡樹脂を充填した後、前記キャビティの容積を大きくすることで前記発泡樹脂を発泡させる発泡樹脂成形品の製造装置であって、
前記第１の金型又は前記第２の金型の少なくともいずれか一方の金型を他方の金型から離れる方向に動かして前記キャビティの容積を大きくする駆動手段と、
前記第２の金型に支持された前記発泡樹脂成形品を前記第１の金型に向かう方向に押して前記第２の金型から前記発泡樹脂成形品を分離する分離手段と、
前記駆動手段と前記分離手段を制御する制御部を有し、
前記駆動手段が前記第１の金型又は前記第２の金型の少なくとも一方を他方から遠ざけて前記キャビティの容積を大きくするとき、前記第１の金型に隣接する第１の発泡樹脂部分の連結気泡の割合が、前記第２の金型に隣接する第２の発泡樹脂部分の連結気泡の割合よりも大きく設定されており、
前記製造装置は、
前記第１の金型に設けた第１の冷却手段と、
前記第２の金型に設けた第２の冷却手段とを有しており、
前記制御部は、前記第１の冷却手段の冷却能力を前記第２の冷却手段の冷却能力よりも高くすることにより、前記第１の金型に近くに存在する発泡樹脂部分を前記第１の金型から離れて存在する発泡樹脂部分よりもより冷却した状態で、前記駆動手段を駆動して前記キャビティの容積を大きくしており、
前記制御部は、前記発泡樹脂の結晶化が始まった後に前記駆動手段を駆動して前記キャビティの容積を大きくすることにより前記発泡樹脂の結晶の周りに独立気泡を形成し、次に、前記前記駆動手段を駆動して前記キャビティの容積をさらに大きくすることにより前記独立気泡を連続気泡に成長させる、ことを特徴とする。

Further, in the apparatus for manufacturing a foamed resin molded product according to an embodiment of the present invention, after filling the cavity formed in the separation surface of the first mold and the second mold with the foamed resin, the volume of the cavity is reduced. An apparatus for manufacturing a foamed resin molded product that foams the foamed resin by enlarging the foamed resin,
Driving means for increasing the volume of the cavity by moving at least one of the first mold and the second mold in a direction away from the other mold;
separating means for pushing the foamed resin molded product supported by the second mold in a direction toward the first mold to separate the foamed resin molded product from the second mold;
comprising a control section that controls the driving means and the separating means,
When the driving means moves at least one of the first mold and the second mold away from the other to increase the volume of the cavity, the first foamed resin portion adjacent to the first mold The proportion of connected cells is set to be larger than the proportion of connected cells in a second foamed resin portion adjacent to the second mold,
The manufacturing device includes:
a first cooling means provided in the first mold;
and a second cooling means provided in the second mold,
The control unit controls the foamed resin portion existing near the first mold by making the cooling capacity of the first cooling means higher than the cooling capacity of the second cooling means. The volume of the cavity is increased by driving the driving means in a state that is cooler than the foamed resin part that is located away from the mold,
The control unit drives the driving means to increase the volume of the cavity after crystallization of the foamed resin starts, thereby forming closed cells around the crystals of the foamed resin, and then The method is characterized in that the closed cells grow into open cells by driving a driving means to further increase the volume of the cavity .

本発明によれば、第１の金型に近い発泡樹脂部分の温度が第２の金型に近い発泡樹脂部分よりも温度が低い状態でキャビティに負圧が導入される。このとき、第１の金型に近い発泡樹脂部分に気泡が形成される。このとき形成される気泡は独立気泡が多い。その後、キャビティの容積が拡大するにしたがって発泡樹脂の全体に気泡が形成されるが、その際、第１の金型に近い発泡樹脂部分に先に形成された独立気泡は金型の離間方向に拡大して連続気泡となり、第１の金型に近い領域に連続気泡の領域を形成する。そのため、発泡樹脂成形品を金型から取り出す際に成形品が押されても、成形品の内部に存在する気泡ガスは周囲に広がる。その結果、一部に溜まったガスが破裂して成形品の外観を損ねる、という問題がない。 According to the present invention, negative pressure is introduced into the cavity while the temperature of the foamed resin portion near the first mold is lower than that of the foamed resin portion near the second mold. At this time, air bubbles are formed in the foamed resin portion near the first mold. Many of the bubbles formed at this time are closed cells. Thereafter, as the volume of the cavity expands, bubbles are formed throughout the foamed resin, but at this time, the closed cells that were previously formed in the foamed resin portion near the first mold are moved in the direction of separation of the molds. The cells expand to become open cells, and an open cell area is formed in a region close to the first mold. Therefore, even if the molded product is pressed when the foamed resin molded product is removed from the mold, the gas bubbles existing inside the molded product will spread to the surrounding area. As a result, there is no problem of the gas accumulated in a part bursting and damaging the appearance of the molded product.

実施形態に係る発泡樹脂成形品の射出成形装置の概略構成を示す概略図。1 is a schematic diagram showing a schematic configuration of an injection molding apparatus for a foamed resin molded product according to an embodiment. 図１に示す射出成形装置の金型の概略構成を示す概略図。2 is a schematic diagram showing a schematic configuration of a mold of the injection molding apparatus shown in FIG. 1. FIG. 図１に示す射出成形装置の金型の概略構成を示す概略図。2 is a schematic diagram showing a schematic configuration of a mold of the injection molding apparatus shown in FIG. 1. FIG. 図１に示す射出成形装置の金型の概略構成を示す概略図。2 is a schematic diagram showing a schematic configuration of a mold of the injection molding apparatus shown in FIG. 1. FIG. 図１に示す射出成形装置の金型の概略構成を示す概略図。2 is a schematic diagram showing a schematic configuration of a mold of the injection molding apparatus shown in FIG. 1. FIG. 他の実施形態に係る発泡樹脂成形品の射出成形装置のキャビティの容積の変化を示すグラフ。7 is a graph showing changes in cavity volume of an injection molding apparatus for a foamed resin molded product according to another embodiment. 他の実施形態に係る発泡樹脂成形品の射出成形装置の金型の概略構成を示す概略図。FIG. 3 is a schematic diagram showing a schematic configuration of a mold of an injection molding apparatus for a foamed resin molded product according to another embodiment.

以下、添付図面を参照して本発明に係る発泡樹脂成形品の製造装置の実施形態を説明する。 DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of an apparatus for manufacturing a foamed resin molded product according to the present invention will be described with reference to the accompanying drawings.

［成形装置］
図１は実施形態に係る発泡樹脂成形品の射出成形装置の概要を示す。図示する射出成形装置１０は、図の右側に配置されている第１の構造（射出部）１２と、図の左側に配置されている第２の構造（成形部）１４を有する。 [Forming equipment]
FIG. 1 shows an outline of an injection molding apparatus for a foamed resin molded product according to an embodiment. The illustrated injection molding apparatus 10 has a first structure (injection section) 12 disposed on the right side of the figure and a second structure (molding section) 14 disposed on the left side of the figure.

第１の構造１２は溶融樹脂射出部１６を含む。溶融樹脂射出部１６は、図の左右方向に伸びる略円筒形状のシリンダ（バレル）１８を有する。シリンダ１８は、第２の構造１４の近傍に射出ノズル２０を有する。射出ノズル２０は、後述する第２の構造１４に設けた樹脂注入口２２（図２～５参照）に接続されている。 The first structure 12 includes a molten resin injection section 16 . The molten resin injection section 16 has a substantially cylindrical cylinder (barrel) 18 extending in the left-right direction in the figure. Cylinder 18 has an injection nozzle 20 in the vicinity of second structure 14 . The injection nozzle 20 is connected to a resin injection port 22 (see FIGS. 2 to 5) provided in the second structure 14, which will be described later.

シリンダ１８は、樹脂を加熱して溶融する加熱部２４を備える。シリンダ１８は、射出ノズル２０の反対側が、発泡樹脂を供給する発泡樹脂供給部２６に接続されている。 The cylinder 18 includes a heating section 24 that heats and melts the resin. The opposite side of the cylinder 18 to the injection nozzle 20 is connected to a foamed resin supply section 26 that supplies foamed resin.

シリンダ１８は、スクリュウ２８を内蔵している。スクリュウ２８はスクリュウ駆動部３０と接続されている。 The cylinder 18 has a built-in screw 28. The screw 28 is connected to a screw drive section 30.

加熱部２４、発泡性能樹脂供給部２６、及びスクリュウ駆動部３０は、制御部３２に接続されており、制御部３２の指令に基づいて動作が制御される。 The heating section 24, the foamable resin supply section 26, and the screw drive section 30 are connected to a control section 32, and their operations are controlled based on instructions from the control section 32.

［成形金型］
第２の構造１４の詳細を説明する。なお、実施形態の理解を容易にするために、以下の説明及びその説明のために利用する図面では、図１に示した第２の構造１４を図１の反時計周り方向に９０度回転した状態で表し、図１の右側に現れる金型部分を上金型、図１の左側に現れる金型部分を下金型と表す。 [Molding mold]
The details of the second structure 14 will be explained. In order to facilitate understanding of the embodiment, in the following description and the drawings used for the description, the second structure 14 shown in FIG. 1 is rotated 90 degrees counterclockwise in FIG. 1. The mold portion appearing on the right side of FIG. 1 is referred to as an upper mold, and the mold portion appearing on the left side of FIG. 1 is referred to as a lower mold.

このような表記を前提とすると、図１に示すように、第２の構造１４は、第１の構造１２から供給される溶融発泡樹脂を所定の形状に成形する成形金型３４を含み、成形金型３４は上金型（第１の金型）３６と下金型（第２の金型）３８を有する。上金型３６又は下金型３８若しくはそれらの両方は、上下方向（基準方向）に移動可能に支持されている。実施形態では、上金型３６が固定されている。下金型３８は、上下に移動可能に支持され、下金型３８を上下方向に移動する金型駆動部４０に駆動連結されている。 Assuming such a notation, as shown in FIG. The mold 34 has an upper mold (first mold) 36 and a lower mold (second mold) 38. The upper mold 36, the lower mold 38, or both are supported so as to be movable in the vertical direction (reference direction). In the embodiment, the upper mold 36 is fixed. The lower mold 38 is supported so as to be movable up and down, and is drivingly connected to a mold drive section 40 that moves the lower mold 38 in the vertical direction.

［キャビティ］
図２に示すように、上金型３６は下金型３８に対向する上金型面（第１の金型面）４２を有し、下金型３８は上金型３６に対向する下金型面（第２の金型面）４４を有し、これら上金型面４２と下金型面４４を合わせて形成される金型分離面に、成形品の外観形状に対応する形状のキャビティ４６が形成される。キャビティ４６は、上金型３６の下金型対向面（第１の金型面）に形成された上部キャビティ形成部分（第１のキャビティ形成部分又は第１の成形部分）４８と、下金型３８の上金型対向面（第２の金型面）に形成された下部キャビティ形成部分（第２のキャビティ形成部分、第２の成形部分、又はキャビティ容積可変部分）５０を有し、上金型３６の上金型面４２を下金型３８の下金型面４４が互いに接触した状態で、上部キャビティ形成部分４８と下部キャビティ形成部分５０の間には成形体１１０（図４，５参照）に対応する形状のキャビティ４６が形成される。 [cavity]
As shown in FIG. 2, the upper mold 36 has an upper mold surface (first mold surface) 42 facing the lower mold 38, and the lower mold 38 has a lower mold surface 42 facing the upper mold 36. A mold surface (second mold surface) 44 is provided, and a mold separation surface formed by combining the upper mold surface 42 and the lower mold surface 44 is provided with a cavity having a shape corresponding to the external shape of the molded product. 46 is formed. The cavity 46 is formed by an upper cavity forming portion (first cavity forming portion or first molding portion) 48 formed on the lower mold opposing surface (first mold surface) of the upper mold 36 and a lower mold. The upper mold has a lower cavity forming portion (second cavity forming portion, second molding portion, or cavity volume variable portion) 50 formed on the upper mold opposing surface (second mold surface) of 38; With the upper mold surface 42 of the mold 36 and the lower mold surface 44 of the lower mold 38 in contact with each other, a molded body 110 (see FIGS. 4 and 5) is placed between the upper cavity forming part 48 and the lower cavity forming part 50. ) is formed.

実施形態では、上部キャビティ形成部分４８は下金型３８に向けて凹状の部分からなり、下部キャビティ形成部分５０は上金型３６に向けて凸状の部分からなる。 In the embodiment, the upper cavity forming portion 48 consists of a concave portion toward the lower mold 38, and the lower cavity forming portion 50 consists of a convex portion toward the upper mold 36.

上部キャビティ形成部分４８は、図の左右方向に伸びる上壁部５２と、上壁部５２の外周端から下金型３８に向かって基準方向に伸びる第１の周壁（内壁）５４が形成されている。下部キャビティ形成部分５０は、図の左右方向に伸びる下壁部５６と、下壁部５６の外周端から上金型３６に向かって基準方向に伸びる第２の周壁（外壁）５８が形成されている。第１の周壁５４と第２の周壁５８は、基準方向から見たとき、同じ形状と大きさを有する。第１の周壁５４の高さ（基準方向の長さ）は第２の周壁５８の高さ（基準方向の長さ）よりも大きい。したがって、図２に示すように、上金型３６の上金型面４２と下金型３８の下金型面４４が接触した状態で、上金型３６の上壁部５２と下金型３８の下壁部５６との間に第１の容積を有する第１の閉鎖空間からなる第１キャビティ空間６０が形成され、上金型３６の上金型面４２と下金型３８の下金型面４４が離れた状態で、上金型３６の上壁部５２と下金型３８の下壁部５６との間に、第１の容積よりも大きな第２の容積を有する第２の閉鎖空間からなる第２キャビティ空間６２（図３参照）が形成され、さらに第２の容積よりも大きな第３の容積を有する第３の閉鎖空間からなる第３キャビティ空間６４（図４参照）が形成されるようになっている。 The upper cavity forming portion 48 is formed with an upper wall portion 52 extending in the left-right direction in the figure, and a first peripheral wall (inner wall) 54 extending in the reference direction from the outer peripheral end of the upper wall portion 52 toward the lower mold 38. There is. The lower cavity forming portion 50 includes a lower wall portion 56 extending in the left-right direction in the figure, and a second peripheral wall (outer wall) 58 extending in the reference direction from the outer peripheral end of the lower wall portion 56 toward the upper mold 36. There is. The first peripheral wall 54 and the second peripheral wall 58 have the same shape and size when viewed from the reference direction. The height of the first peripheral wall 54 (length in the reference direction) is greater than the height (length in the reference direction) of the second peripheral wall 58. Therefore, as shown in FIG. 2, when the upper mold surface 42 of the upper mold 36 and the lower mold surface 44 of the lower mold 38 are in contact with each other, the upper wall portion 52 of the upper mold 36 and the lower mold surface 44 of the lower mold 38 are in contact with each other. A first cavity space 60 consisting of a first closed space having a first volume is formed between the lower wall portion 56 of the upper mold 36 and the lower mold surface 42 of the upper mold 36 and the lower mold of the lower mold 38. A second closed space having a second volume larger than the first volume is provided between the upper wall part 52 of the upper mold 36 and the lower wall part 56 of the lower mold 38 with the surfaces 44 separated. A second cavity space 62 (see FIG. 3) is formed, and a third cavity space 64 (see FIG. 4) is formed as a third closed space having a third volume larger than the second volume. It has become so.

実施形態では、下金型３８の下壁部５６には、上金型３６から離れる方向に向かって基準方向に伸びる一つ又は複数の溝（リブ形成部）６８が形成されている。 In the embodiment, the lower wall portion 56 of the lower mold 38 is formed with one or more grooves (rib forming portions) 68 extending in the reference direction in a direction away from the upper mold 36 .

［樹脂注入口、エアベント］
実施形態では、上金型３６に樹脂注入口２２とキャビティ４６を接続するスプルー７０が形成されており、シリンダ１８から排出される溶融発泡樹脂７２が樹脂注入口２２からスプルー７０を介してキャビティ４６に供給されるようになっている。また、図示しないが、上金型３６の上金型面４２又は下金型３８の下金型面４４若しくはそれらの両方には、射出成形時にキャビティ４６内のエア又はガスを排出するためのエアベント（図示せず）が形成されている。 [Resin injection port, air vent]
In the embodiment, a sprue 70 connecting the resin injection port 22 and the cavity 46 is formed in the upper mold 36, and the molten foamed resin 72 discharged from the cylinder 18 flows from the resin injection port 22 through the sprue 70 into the cavity 46. is being supplied to. Although not shown, an air vent is provided on the upper mold surface 42 of the upper mold 36, the lower mold surface 44 of the lower mold 38, or both for discharging air or gas within the cavity 46 during injection molding. (not shown) is formed.

［エジェクタ］
下金型３８はまた、下部キャビティ形成部分５０の下壁部５６から下方（上金型３６から離れる方向に）に向かってまっすぐに伸びる一つ又は複数のエジェクタ通路７６が形成されている。エジェクタ通路７６には、エジェクタピン７８が挿入されている。エジェクタピン７８はエジェクタピン駆動部８０に連結されており、エジェクタピン駆動部８０の駆動に基づいて、図２～４に示すように、エジェクタピン７８の上端面が下部キャビティ形成部分５０の下壁部５６と同じ高さに位置する下降位置と、エジェクタピン７８の上端が下部キャビティ形成部分５０の下壁部５６から上方に突出した上昇位置との間を移動するようにしてある。図５において、エジェクタピン７８の上端は、下降位置から上昇位置に向かうまでの中途位置にあり、上昇位置に向けてさらに移動できるように構成されている。 [Ejector]
The lower mold 38 is also formed with one or more ejector passages 76 that extend straight downward (in a direction away from the upper mold 36) from the lower wall 56 of the lower cavity forming portion 50. An ejector pin 78 is inserted into the ejector passage 76. The ejector pin 78 is connected to an ejector pin drive section 80, and based on the drive of the ejector pin drive section 80, as shown in FIGS. The ejector pin 78 is configured to move between a lowered position located at the same height as the portion 56 and a raised position where the upper end of the ejector pin 78 protrudes upward from the lower wall portion 56 of the lower cavity forming portion 50. In FIG. 5, the upper end of the ejector pin 78 is located halfway from the lowered position to the raised position, and is configured to be able to move further toward the raised position.

［冷却手段］
上金型３６と下金型３８には、キャビティ４６に射出された溶融樹脂を冷却する第１の冷媒循環路８２と第２の冷媒循環路８４がそれぞれ形成されている。第１の冷媒循環路８２と第２の冷媒循環路８４はそれぞれ第１の冷媒供給回収路８６と第２の冷媒供給回収回路８８を介して第１の冷媒供給回収装置９０と第２の冷媒供給回収装置９２に接続されている。図示しないが、第１と第２の冷媒供給回収装置９０，９２は、冷媒を循環させるポンプと、高温樹脂との熱交換によって熱を回収した冷媒を冷却する冷却器を備えている。 [Cooling means]
A first refrigerant circulation path 82 and a second refrigerant circulation path 84 for cooling the molten resin injected into the cavity 46 are formed in the upper mold 36 and the lower mold 38, respectively. The first refrigerant circulation path 82 and the second refrigerant circulation path 84 connect the first refrigerant supply and recovery device 90 and the second refrigerant via a first refrigerant supply and recovery path 86 and a second refrigerant supply and recovery circuit 88, respectively. It is connected to the supply and recovery device 92. Although not shown, the first and second refrigerant supply and recovery devices 90 and 92 include a pump that circulates the refrigerant and a cooler that cools the refrigerant that has recovered heat through heat exchange with the high-temperature resin.

［温度センサ］
図２～５に示すように、上金型３６のキャビティ４６に隣接する部分（例えば、上壁部５２の表面）には、キャビティ４６に充填された溶融発泡樹脂７２であってその部分に位置する溶融発泡樹脂部分の温度を検出する第１の温度検出器９４が配置されている。また、下金型３８のキャビティ４６に隣接する部分（例えば、下壁部５６の表面）には、キャビティ４６に充填された溶融発泡樹脂７２であってその部分に位置する溶融発泡樹脂部分の温度を検出する第２の温度検出器９６が配置されている。 [Temperature sensor]
As shown in FIGS. 2 to 5, a portion of the upper mold 36 adjacent to the cavity 46 (for example, the surface of the upper wall portion 52) is filled with molten foamed resin 72 that is located in that portion. A first temperature detector 94 is arranged to detect the temperature of the molten foamed resin portion. Further, in a portion of the lower mold 38 adjacent to the cavity 46 (for example, the surface of the lower wall portion 56), the temperature of the molten foamed resin portion located in that portion of the molten foamed resin 72 filled in the cavity 46 is A second temperature detector 96 is arranged to detect the temperature.

金型駆動部４０、エジェクタピン駆動部８０、冷媒供給回収装置９０，９２、及び温度検出器９４，９６は制御部３２に接続されており、例えば、温度検出器９４，９６で検出される温度をもとに、制御部３２が金型駆動部４０、エジェクタピン駆動部８０、及び冷媒供給回収装置９０，９２が駆動するように構成されている。 The mold drive unit 40, the ejector pin drive unit 80, the refrigerant supply and recovery devices 90, 92, and the temperature detectors 94, 96 are connected to the control unit 32, and, for example, the temperature detected by the temperature detectors 94, 96 Based on this, the control section 32 is configured to drive the mold drive section 40, ejector pin drive section 80, and refrigerant supply and recovery devices 90 and 92.

［成形プロセス］
制御部３２の制御に基づく成形プロセスを説明する。
発泡樹脂供給部２６には、樹脂と発泡剤を混合した発泡樹脂が貯蔵される。樹脂には、例えばポリプロピレン（ＰＰ）、ポリエチレン（ＰＥ）、ポリ塩化ビニル（ＰＶＣ）、ポリスチレン（ＰＳ）、ポリウレタン（ＰＵＲ）、ポリカーボネート（ＰＣ）、ナイロンからなる熱可塑性樹脂が利用される。発泡剤は、化学発泡剤、物理発泡剤、発泡性マイクロカプセルのいずれであってもよい。微細な気泡を形成する場合、発泡剤として超臨界状態の窒素又は二酸化炭素を用いることが好ましい。 [Molding process]
The molding process based on the control of the control unit 32 will be explained.
The foamed resin supply section 26 stores foamed resin in which a resin and a foaming agent are mixed. As the resin, thermoplastic resins such as polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS), polyurethane (PUR), polycarbonate (PC), and nylon are used. The blowing agent may be a chemical blowing agent, a physical blowing agent, or an expandable microcapsule. When forming fine bubbles, it is preferable to use supercritical nitrogen or carbon dioxide as the blowing agent.

成形金型３４の上金型３６と下金型３８は、図２に示すように、上金型３６の上金型面４２と下金型３８の下金型面４４を接触させた状態で閉じている。 As shown in FIG. 2, the upper mold 36 and the lower mold 38 of the molding mold 34 are in a state where the upper mold surface 42 of the upper mold 36 and the lower mold surface 44 of the lower mold 38 are in contact with each other. Closed.

この状態から、制御部３２によって発泡樹脂供給部２６から発泡樹脂がシリンダ１８の内部に供給される。 From this state, the control unit 32 supplies foamed resin from the foamed resin supply unit 26 into the cylinder 18 .

制御部３２は、スクリュウ駆動部３０を駆動して、スクリュウ２８を軸周りに回転させる。制御部３２はまた、加熱部２４を起動して、シリンダ１８に投入された発泡樹脂７２を加熱して溶融する。例えば、ポリプロピレンの場合、その融点は１６５℃であるため、一般的に、２００～３０５℃まで加熱される。 The control unit 32 drives the screw drive unit 30 to rotate the screw 28 around the axis. The control unit 32 also activates the heating unit 24 to heat and melt the foamed resin 72 introduced into the cylinder 18 . For example, polypropylene has a melting point of 165°C, so it is generally heated to 200-305°C.

溶融した発泡樹脂７２は、スクリュウ２８の回転に基づいて、成形金型３４の一つ又は複数の注入口２２から、スプルー７０を介してキャビティ４６（第１の容積を有する第１のキャビティ空間６０）に射出され、キャビティ４６内のエア又はガスと置換される。置換されたエア又はガスは、図示しないエアベントを介して排出される。 Based on the rotation of the screw 28, the molten foamed resin 72 flows from one or more injection ports 22 of the molding die 34 through the sprue 70 into the cavity 46 (a first cavity space 60 having a first volume). ) and replaces the air or gas in the cavity 46. The replaced air or gas is exhausted through an air vent (not shown).

充填された発泡樹脂７２は、下金型３８に形成された溝６８にも充填されて補強リブ７４を形成する。 The filled foamed resin 72 also fills the grooves 68 formed in the lower mold 38 to form reinforcing ribs 74.

このとき、制御部３２からの指令に基づいて冷媒供給回収装置９０，９２が駆動しており、上金型３６と下金型３８の冷媒循環路８２，８４には冷媒が循環される。したがって、キャビティ４６に充填された発泡樹脂７２は、特にキャビティ４６内面に接触する樹脂部分が約７０℃～１２０℃に冷却され、そこにスキン層１００が形成される。 At this time, the refrigerant supply and recovery devices 90 and 92 are driven based on a command from the control unit 32, and refrigerant is circulated in the refrigerant circulation paths 82 and 84 of the upper mold 36 and the lower mold 38. Therefore, the foamed resin 72 filled in the cavity 46 is cooled to about 70° C. to 120° C., especially the resin portion that contacts the inner surface of the cavity 46, and the skin layer 100 is formed there.

ただし、制御部３２は、第１の冷媒供給回収装置９０の冷却能力を第２の冷媒供給回収装置９２の冷却能力よりも上げて、上金型３６を下金型３８よりもより冷却する。これにより、上金型３６に隣接する発泡樹脂７２の温度は下金型３８に隣接する発泡樹脂７２の温度よりも低くなる。そのため、上金型３６に隣接する発泡樹脂７２は下金型３８に接する発泡樹脂７２よりもより早く結晶化温度に達する。 However, the control unit 32 increases the cooling capacity of the first refrigerant supply and recovery device 90 higher than the cooling capacity of the second refrigerant supply and recovery device 92 to cool the upper mold 36 more than the lower mold 38. As a result, the temperature of the foamed resin 72 adjacent to the upper mold 36 becomes lower than the temperature of the foamed resin 72 adjacent to the lower mold 38. Therefore, the foamed resin 72 adjacent to the upper mold 36 reaches the crystallization temperature earlier than the foamed resin 72 adjacent to the lower mold 38.

上金型３６と下金型３８に隣接する発泡樹脂７２の温度はそれぞれ温度検出器９４，９６で検出されている。温度検出器９４、９６で検出された温度は制御部３２に送信される。制御部３２は、検出温度をもとに、特に上金型３６に接するスキン層１００の内側近傍に存在する発泡樹脂７２の温度を決定する。温度の決定は、実験結果をもとに作成されたテーブルをもとに行うこともできるし、例えば有限要素法を用いた温度分布解析から求めることもできる。 The temperatures of the foamed resin 72 adjacent to the upper mold 36 and lower mold 38 are detected by temperature detectors 94 and 96, respectively. The temperatures detected by the temperature detectors 94 and 96 are transmitted to the control section 32. Based on the detected temperature, the control unit 32 determines the temperature of the foamed resin 72, which is present near the inner side of the skin layer 100, which is in contact with the upper mold 36, in particular. The temperature can be determined based on a table created based on experimental results, or can be determined from temperature distribution analysis using the finite element method, for example.

次に、制御部３２は、上金型３６に接するスキン層１００の内側近傍に存在する発泡樹脂７２の温度が樹脂の結晶化温度付近に達したと判断すると、金型駆動部４０を駆動して下金型３８を所定量下降し、キャビティ４６の容積を第１の容積よりも大きな第２の容積を有する第２のキャビティ空間６２に拡大して、キャビティ４６の中に負圧を誘導する（図３参照）。ただし、この段階における下金型３８の下降量は、下金型３８における下部キャビティ形成部分５０の周壁５８の高さよりも小さい。したがって、上金型３６と下金型３８の間には閉鎖空間が維持される。 Next, when the control unit 32 determines that the temperature of the foamed resin 72 existing near the inner side of the skin layer 100 in contact with the upper mold 36 has reached around the crystallization temperature of the resin, it drives the mold drive unit 40. lowering the lower mold 38 by a predetermined amount, expanding the volume of the cavity 46 into a second cavity space 62 having a second volume larger than the first volume, and inducing negative pressure in the cavity 46. (See Figure 3). However, the amount of descent of the lower mold 38 at this stage is smaller than the height of the peripheral wall 58 of the lower cavity forming portion 50 in the lower mold 38. Therefore, a closed space is maintained between the upper mold 36 and the lower mold 38.

例えば、ポリプロピレンの場合、結晶化温度は約９０～１２０℃である。また、ポリプロピンを含む発泡樹脂の場合、ポリプロピレンが結晶化する過程でその周囲に小さな気泡が発生し始める。したがって、スキン層１００の内側近傍に存在するポリプロピレンの温度が約９０～１２０℃に達した状態で発泡樹脂７２に負圧を与えると、上金型３６の近傍の発泡樹脂７２に発生した結晶の周囲にのみ気泡が発生し、上金型３６から離れた発泡樹脂（例えば、上金型３６よりも高温の下金型３８の近くに存在する発泡樹脂）に気泡は発生しない。また、この段階で発生する気泡はその大部分が独立気泡の状態で存在する。 For example, for polypropylene, the crystallization temperature is about 90-120°C. Furthermore, in the case of foamed resin containing polypropylene, small bubbles begin to form around the polypropylene as it crystallizes. Therefore, if negative pressure is applied to the foamed resin 72 when the temperature of the polypropylene existing near the inner side of the skin layer 100 reaches approximately 90 to 120°C, crystals generated in the foamed resin 72 near the upper mold 36 will be removed. Air bubbles are generated only in the surrounding area, and no air bubbles are generated in the foamed resin that is away from the upper mold 36 (for example, the foamed resin that is present near the lower mold 38, which is hotter than the upper mold 36). Moreover, most of the bubbles generated at this stage exist in the state of closed cells.

次に、制御部３２は、金型駆動部４０を所定時間停止し、キャビティ４６の容積を第２の容積に維持する。 Next, the control unit 32 stops the mold drive unit 40 for a predetermined period of time and maintains the volume of the cavity 46 at the second volume.

続いて、制御部３２は、再び金型駆動部４０を駆動し、キャビティ４６の容積を第２の容積よりも大きな第３の容積を有する第３のキャビティ空間６４に拡大して、キャビティ４６の中に再び負圧を誘導する（図４参照）。この段階における下金型３８の下降量も小さく、上金型３６と下金型３８の間には閉鎖空間が維持される。 Subsequently, the control unit 32 drives the mold drive unit 40 again to expand the volume of the cavity 46 into a third cavity space 64 having a third volume larger than the second volume, thereby increasing the volume of the cavity 46 . Negative pressure is again induced inside (see Figure 4). The amount of descent of the lower mold 38 at this stage is also small, and a closed space is maintained between the upper mold 36 and the lower mold 38.

したがって、発泡樹脂７２の内部に、特にスキン層１００の内側に位置する発泡樹脂７２に含まれる発泡剤が発泡し、スキン層１００の内側全体に気泡が形成されてコア層１０２が形成される。このとき、金型駆動部４０の停止中及びその後の駆動中も、キャビティ４６内の発泡樹脂７２は冷却され続け、その温度が全体的に低下し続けるものの、発泡樹脂７２は上金型３６に近い部分が下金型３８に近い部分よりも低温となっている。そのため、下金型３８に近い領域の発泡樹脂７２では新しい気泡が発生し、上金型３６に近い領域の発泡樹脂７２では新しい気泡が発生するだけでなく先に形成された独立気泡の大部分が拡大して互いに連結して連結気泡を形成する。つまり、上金型３６に近いコア層部分では連結気泡の割合が高く（独立気泡の割合が低い）、下金型３８に近いコア層部分では連結気泡の割合が低い（独立気泡の割合が高い）。 Therefore, the foaming agent contained in the foamed resin 72, particularly located inside the skin layer 100, foams inside the foamed resin 72, and air bubbles are formed throughout the inside of the skin layer 100, thereby forming the core layer 102. At this time, the foamed resin 72 in the cavity 46 continues to be cooled even while the mold drive section 40 is stopped and is driven thereafter, and although the temperature continues to decrease overall, the foamed resin 72 remains in the upper mold 36. The part near the lower mold 38 has a lower temperature than the part near the lower mold 38. Therefore, new bubbles are generated in the foamed resin 72 in the area near the lower mold 38, and not only new bubbles are generated in the foamed resin 72 in the area close to the upper mold 36, but also most of the previously formed closed cells. expand and connect with each other to form connected bubbles. In other words, the proportion of connected cells is high in the core layer part near the upper mold 36 (the proportion of closed cells is low), and the proportion of connected cells is low (the proportion of closed cells is high) in the core layer part near the lower mold 38. ).

以上のようにして発泡処理が終了すると、制御部３２は、下金型３８を下方に移動して、図５に示すように、上金型３６と下金型３８の間に成形体取出空間を形成する。続いて、制御部３２は、エジェクタピン駆動部８０を駆動し、エジェクタピン７８を上昇させて、成形体１１０を下金型３８から分離する。（図５は、エジェクタピン７８の上端が、成形体１１０を下金型３８から分離する上昇位置に向かうまでの中途位置にあることを示している。） When the foaming process is completed as described above, the control unit 32 moves the lower mold 38 downward to create a molded body removal space between the upper mold 36 and the lower mold 38, as shown in FIG. form. Subsequently, the control unit 32 drives the ejector pin drive unit 80 to raise the ejector pin 78 and separate the molded body 110 from the lower mold 38. (FIG. 5 shows that the upper end of the ejector pin 78 is halfway to the raised position where the molded body 110 is separated from the lower mold 38.)

このとき、成形体１１０は下金型３８に密着しているので、エジェクタピン７８に大きな力が加えられる。特に、補強リブ７４を有する成形体１１０を金型から分離する場合、エジェクタピン７８から成形体１１０に加えられる力はさらに大きい。また、エジェクタピン７８から成形体１１０に加えられた力は、成形体表面のスキン層１００から成形体内部のコア層１０４に伝達され、コア層１０４に含まれる気泡体に圧力を加える。しかし、上述のように、コア層１０４、特に上金型３６に近い領域のコア層部分には多くの連続気泡が形成されているため、エジェクタピン７８から圧力が加えられたガスは連続気泡を通って全方向に分散する。そのため、エジェクタピン７８に押されたガスの気泡が破裂するとか、エジェクタピン７８に押されたガスの移動によりスキン層１００がコア層１０４から剥離されるとか、ガスがスキン層１００を破って噴き出るということはない。そのため、発泡樹脂からなる成形体１１０の外観が損なわれることがない。 At this time, since the molded body 110 is in close contact with the lower mold 38, a large force is applied to the ejector pin 78. In particular, when separating the molded body 110 having the reinforcing ribs 74 from the mold, the force applied to the molded body 110 from the ejector pin 78 is even greater. Further, the force applied to the molded body 110 from the ejector pin 78 is transmitted from the skin layer 100 on the surface of the molded body to the core layer 104 inside the molded body, and applies pressure to the bubbles contained in the core layer 104. However, as described above, many open cells are formed in the core layer 104, especially in the core layer portion in the area close to the upper mold 36, so the gas applied pressure from the ejector pin 78 does not cause open cells. pass through and disperse in all directions. Therefore, the gas bubbles pushed by the ejector pin 78 may burst, the skin layer 100 may be peeled off from the core layer 104 due to the movement of the gas pushed by the ejector pin 78, or the gas may break through the skin layer 100 and blow out. There's no way it's going to come out. Therefore, the appearance of the molded body 110 made of foamed resin is not impaired.

［他の実施形態］
上述した実施形態において、キャビティ４６の容積を第１の容積から第２の容積に増加する第１の容積増加速度をＶ１、キャビティ４６の容積を第２の容積から第３の容積に増加する第２の容積増加速度をＶ２とすると、第１の容積増加速度Ｖ１と第２の容積増加速度Ｖ２との関係は、使用する樹脂や発泡剤、成形体の大きさ等の諸条件に応じて、Ｖ１＝Ｖ２、Ｖ１＜Ｖ２又はＶ１＞Ｖ２のいずれかの最適な関係に設定される。 [Other embodiments]
In the embodiment described above, the first volume increase rate for increasing the volume of the cavity 46 from the first volume to the second volume is V1, and the first volume increase rate for increasing the volume of the cavity 46 from the second volume to the third volume is V1. If the volume increase rate of 2 is V2, the relationship between the first volume increase rate V1 and the second volume increase rate V2 depends on various conditions such as the resin and foaming agent used, the size of the molded object, etc. The optimum relationship is set to V1=V2, V1<V2, or V1>V2.

また、上述した実施形態では、キャビティ４６の容積を拡大する途中で所定時間キャビティの容積を一定に維持したが、図６に示すように発泡処理中はキャビティ４６の容積を連続的に増加してもよい。この場合、例えばキャビティ４６の容積を第１の容積から第２の容積に増加する第１の容積増加速度をＶ１、キャビティ４６の容積を第２の容積から第３の容積に増加する第２の容積増加速度をＶ２、キャビティ４６の容積を第３の容積から第４の容積に増加する第３の容積増加速度をＶ３とすると、これら容積増加速度Ｖ１、Ｖ２，Ｖ３は、使用する樹脂や発泡剤、成形体の大きさ等の諸条件に応じて、Ｖ１＝Ｖ２＝Ｖ３、Ｖ１＝Ｖ３＞Ｖ２、Ｖ１＞Ｖ３＞Ｖ２又はＶ２＜Ｖ１＜Ｖ３のいずれかの最適な関係に設定される。 Further, in the above-described embodiment, the volume of the cavity 46 is maintained constant for a predetermined period of time while the volume of the cavity 46 is expanded, but as shown in FIG. 6, the volume of the cavity 46 is continuously increased during the foaming process. Good too. In this case, for example, the first volume increase rate for increasing the volume of the cavity 46 from the first volume to the second volume is V1, and the second volume increase rate for increasing the volume of the cavity 46 from the second volume to the third volume is V1. Assuming that the volume increase rate is V2 and the third volume increase rate for increasing the volume of the cavity 46 from the third volume to the fourth volume is V3, these volume increase rates V1, V2, and V3 depend on the resin used and the foaming. Depending on various conditions such as the agent and the size of the molded body, the optimum relationship is set to V1=V2=V3, V1=V3>V2, V1>V3>V2, or V2<V1<V3.

以上の説明では、下金型３８に下部キャビティ形成部分５０を一体的に形成したが、図７に示すように、下金型３８を、金型閉鎖時に上金型３６に接触する第１の下金型部分（本体部分）２１０と、上金型３６に対して前進後退可能な第２の下金型部分（可動部分）２１２で構成し、第２の下金型部分２１２を上金型３６に対して前進後退させることによって、上金型３６と下金型３８との間に形成されたキャビティ４６の容積を、第１の容積と、該第１の容積よりも大きな第２の容積との間で可変するようにしてもよい。 In the above description, the lower cavity forming part 50 is integrally formed in the lower mold 38, but as shown in FIG. It is composed of a lower mold part (main body part) 210 and a second lower mold part (movable part) 212 that can move forward and backward with respect to the upper mold 36, and the second lower mold part 212 is connected to the upper mold part. 36, the volume of the cavity 46 formed between the upper mold 36 and the lower mold 38 is divided into a first volume and a second volume larger than the first volume. It may be made to vary between.

また、上述した上金型と下金型はそれぞれ任意の数に分割しても構わない。 Further, the above-mentioned upper mold and lower mold may each be divided into an arbitrary number of parts.

さらに、以上の説明では、上金型と下金型の近くにそれぞれ温度検出器を設け、上金型と下金型の近くに位置するそれぞれの樹脂の温度を測定したが、これら２つの温度検出器を設ける必要はなく、少なくとも一方の温度検出器だけを設け、その検出値を用いて金型の移動を制御してもよい。 Furthermore, in the above explanation, temperature detectors were installed near the upper mold and lower mold to measure the temperature of each resin located near the upper mold and lower mold. There is no need to provide a detector, and at least one temperature detector may be provided and the detected value may be used to control the movement of the mold.

３６：第１の金型（上金型）
３８：第２の金型（下金型）
４６：キャビティ
７２：発泡樹脂
１１０：発泡樹脂成形品 36: First mold (upper mold)
38: Second mold (lower mold)
46: Cavity 72: Foamed resin 110: Foamed resin molded product

Claims (5)

第１の金型と第２の金型の分離面に形成されたキャビティに発泡樹脂を充填した後、前記キャビティの容積を大きくすることで前記発泡樹脂を発泡させる発泡樹脂成形品の製造方法であって、
前記キャビティに前記発泡樹脂を充填する工程（ａ）と、
前記第１の金型又は前記第２の金型の少なくとも一方を他方から遠ざけて前記キャビティの容積を大きくし、前記第１の金型に隣接する第１の発泡樹脂部分の連結気泡の割合を、前記第２の金型に隣接する第２の発泡樹脂部分の連結気泡の割合よりも大きく設定する工程（ｂ）と、
前記発泡樹脂成形品を前記第２の金型に残したまま前記第１の金型を前記発泡樹脂成形品から分離させる工程（ｃ）と、
前記発泡樹脂成形品を前記第２の金型から前記第１の金型に向かう方向に押して、前記発泡樹脂成形品を前記第２の金型から分離させる工程（ｄ）、を備えており、
前記工程（ｂ）は、予め、前記第１の金型に接する前記第１の発泡樹脂部分を前記第２の金型に接する前記第２の発泡樹脂部分よりも冷却し、前記第１の発泡樹脂部分の温度が前記第２の発泡樹脂部分よりも所定温度低い状態で行われ、
前記キャビティは、前記工程（ｂ）の開始前に第１の容積を有し、
前記工程（ｂ）は、
前記キャビティの容積を前記第１の容積から第２の容積まで増加させる第１工程（ｂ１）と、
前記キャビティの容積を前記第２の容積から第３の容積まで増加させる第２工程（ｂ２）と、
前記第１工程（ｂ１）と前記第２工程（ｂ２）の間にあって、前記キャビティの容積を前記第２の容積に維持する中間工程、を備えることを特徴とする発泡樹脂成形品の製造方法。 A method for manufacturing a foamed resin molded product, in which a cavity formed on a separation surface between a first mold and a second mold is filled with foamed resin, and then the foamed resin is expanded by increasing the volume of the cavity. There it is,
(a) filling the cavity with the foamed resin;
At least one of the first mold and the second mold is moved away from the other to increase the volume of the cavity, and the proportion of connected cells in the first foamed resin portion adjacent to the first mold is increased. , a step (b) of setting the proportion of connected cells to be larger than the proportion of connected cells in the second foamed resin portion adjacent to the second mold;
(c) separating the first mold from the foam resin molded product while leaving the foam resin molded product in the second mold;
a step (d) of pushing the foamed resin molded product in a direction from the second mold toward the first mold to separate the foamed resin molded product from the second mold ,
In the step (b), in advance, the first foamed resin portion in contact with the first mold is cooled lower than the second foamed resin portion in contact with the second mold, and the first foamed resin portion is cooled in advance. carried out in a state where the temperature of the resin part is a predetermined temperature lower than the second foamed resin part,
the cavity has a first volume before the start of step (b);
The step (b) includes:
a first step (b1) of increasing the volume of the cavity from the first volume to a second volume;
a second step (b2) of increasing the volume of the cavity from the second volume to a third volume;
A method for producing a foamed resin molded product, comprising an intermediate step between the first step (b1) and the second step (b2), in which the volume of the cavity is maintained at the second volume. 前記第１工程（ｂ１）において前記キャビティの容積を前記第１の容積から前記第２の容積に増加させる第１の容積増加速度を（Ｖ１）、
前記第２工程（ｂ２）において前記キャビティの容積を前記第２の容積から前記第３の容積に増加させる第２の容積増加速度を（Ｖ２）とすると、
前記第１容積増加速度（Ｖ１）と前記第２の容積増加速度（Ｖ２）は、
Ｖ１＝Ｖ２、
Ｖ１＜Ｖ２、
又はＶ１＞Ｖ２であることを特徴とする請求項１に記載の発泡樹脂成形品の製造方法。 A first volume increase rate at which the volume of the cavity is increased from the first volume to the second volume in the first step (b1) (V1),
If the second volume increase rate at which the volume of the cavity is increased from the second volume to the third volume in the second step (b2) is (V2),
The first volume increase rate (V1) and the second volume increase rate (V2) are
V1=V2,
V1<V2,
The method for manufacturing a foamed resin molded product according to claim 1 , wherein V1>V2. 前記工程（ｂ）は、
前記第２工程（ｂ２）の後、前記キャビティの容積を前記第３の容積から第４の容積まで増加させる第３工程（ｂ３）、を備えることを特徴とする請求項１に記載の発泡樹脂成形品の製造方法。 The step (b) includes:
The foamed resin according to claim 1, further comprising , after the second step (b2), a third step (b3) of increasing the volume of the cavity from the third volume to the fourth volume. Method of manufacturing molded products. 前記第１工程（ｂ１）において前記キャビティの容積を前記第１の容積から前記第２の容積に増加させる第１の容積増加速度を（Ｖ１）、
前記第２工程（ｂ２）において前記キャビティの容積を前記第２の容積から前記第３の容積に増加させる第２の容積増加速度を（Ｖ２）、
前記第３工程（ｂ３）において前記キャビティの容積を前記第３の容積から前記第４の容積に増加させる第３の容積増加速度を（Ｖ３）とすると、
前記第１容積増加速度（Ｖ１）、前記第２の容積増加速度（Ｖ２）、及び前記第３の容積増加速度（Ｖ３）は、
Ｖ１＝Ｖ２＝Ｖ３、
Ｖ１＝Ｖ３＞Ｖ２、
Ｖ１＞Ｖ３＞Ｖ２、
又はＶ２＜Ｖ１＜Ｖ３であることを特徴とする請求項３に記載の発泡樹脂成形品の製造方法。 A first volume increase rate at which the volume of the cavity is increased from the first volume to the second volume in the first step (b1) (V1),
A second volume increase rate at which the volume of the cavity is increased from the second volume to the third volume in the second step (b2) (V2),
If the third volume increase rate at which the volume of the cavity is increased from the third volume to the fourth volume in the third step (b3) is (V3),
The first volume increase rate (V1), the second volume increase rate (V2), and the third volume increase rate (V3) are
V1=V2= V3 ,
V1=V3>V2,
V1>V3>V2,
The method for manufacturing a foamed resin molded product according to claim 3, characterized in that, or V2<V1<V3. 第１の金型と第２の金型の分離面に形成されたキャビティに発泡樹脂を充填した後、前記キャビティの容積を大きくすることで前記発泡樹脂を発泡させる発泡樹脂成形品の製造装置であって、
前記第１の金型又は前記第２の金型の少なくともいずれか一方の金型を他方の金型から離れる方向に動かして前記キャビティの容積を大きくする駆動手段と、
前記第２の金型に支持された前記発泡樹脂成形品を前記第１の金型に向かう方向に押して前記第２の金型から前記発泡樹脂成形品を分離する分離手段と、
前記駆動手段と前記分離手段を制御する制御部を有し、
前記駆動手段が前記第１の金型又は前記第２の金型の少なくとも一方を他方から遠ざけて前記キャビティの容積を大きくするとき、前記第１の金型に隣接する第１の発泡樹脂部分の連結気泡の割合が、前記第２の金型に隣接する第２の発泡樹脂部分の連結気泡の割合よりも大きく設定されており、
前記製造装置は、
前記第１の金型に設けた第１の冷却手段と、
前記第２の金型に設けた第２の冷却手段とを有しており、
前記制御部は、前記第１の冷却手段の冷却能力を前記第２の冷却手段の冷却能力よりも高くすることにより、前記第１の金型に近くに存在する発泡樹脂部分を前記第１の金型から離れて存在する発泡樹脂部分よりもより冷却した状態で、前記駆動手段を駆動して前記キャビティの容積を大きくしており、
前記制御部は、前記発泡樹脂の結晶化が始まった後に前記駆動手段を駆動して前記キャビティの容積を大きくすることにより前記発泡樹脂の結晶の周りに独立気泡を形成し、次に、前記前記駆動手段を駆動して前記キャビティの容積をさらに大きくすることにより前記独立気泡を連続気泡に成長させる、ことを特徴とする発泡樹脂成形品の製造装置。 An apparatus for manufacturing a foamed resin molded product that fills a cavity formed on a separation surface between a first mold and a second mold with foamed resin, and then expands the foamed resin by increasing the volume of the cavity. There it is,
Driving means for increasing the volume of the cavity by moving at least one of the first mold and the second mold in a direction away from the other mold;
separating means for pushing the foamed resin molded product supported by the second mold in a direction toward the first mold to separate the foamed resin molded product from the second mold;
comprising a control section that controls the driving means and the separating means,
When the driving means moves at least one of the first mold and the second mold away from the other to increase the volume of the cavity, the first foamed resin portion adjacent to the first mold The proportion of connected cells is set to be larger than the proportion of connected cells in a second foamed resin portion adjacent to the second mold,
The manufacturing device includes:
a first cooling means provided in the first mold;
and a second cooling means provided in the second mold,
The control unit controls the foamed resin portion existing near the first mold by making the cooling capacity of the first cooling means higher than the cooling capacity of the second cooling means. The volume of the cavity is increased by driving the driving means in a state that is cooler than the foamed resin part that is located away from the mold,
The control unit drives the driving means to increase the volume of the cavity after crystallization of the foamed resin starts, thereby forming closed cells around the crystals of the foamed resin, and then An apparatus for manufacturing a foamed resin molded product, characterized in that the closed cells grow into open cells by driving a driving means to further increase the volume of the cavity.
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