JPH09174614A - Die scaling-up injection foaming mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a die scaling-up injection foaming mold which enables attainment of a die scaling-up injection foaming molded article having a complicated shape and a uniform foamed layer thickness. SOLUTION: In a die scaling-up injection foaming mold composed of a movable half and a stationary half 1 which are connected to an injection port of an injection molding machine, the movable half is made up of a general part member 21 forming a portion being perpendicular practically to the direction of movement of the mold and of a plurality of split die members 221-226 forming a portion being parallel practically to this direction, and the split die members 221-226 in a plurality are so constructed that they move in the direction of mold opening sequentially with a mold opening operation at the time when a foamed layer is formed, so as to make uniform the foamed layer thickness of a resin molded article.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold used for injection foam molding with mold expansion, and more specifically, mold expansion foam injection for obtaining a skin foam layer integrated resin molded product having a uniform foam layer thickness. Regarding the mold.

[0002]

2. Description of the Related Art As a conventional mold expansion injection foam molding method,
For example, there is a molding method as disclosed in JP-A-62-246710. In this molding method, a molding die including a fixed die 1 and a movable die 2 as shown in FIG. 5 is used.
At the time of molding, as shown in FIG. 5A, when the fixed mold 1 and the movable mold 2 are closed and a resin containing a foaming agent is injected into the cavity 3, the resin in contact with the mold is rapidly cooled. As a result, a skin having no foamed portion is formed. Next, the cavity 3 is filled with the resin, as shown in FIG.
As shown in (1), a part or all of the movable mold 2 is opened by a moving distance 5 during or immediately after the filling, and the foaming agent in the resin is foamed in the generated void 4 to form a skin without the foamed part. In this method, a resin molded product in which the foam layer is integrated is molded.

[0003]

However, in such a conventional mold structure used for injection foam molding, as shown in FIG. 5 (a), a mold made of a fixed mold 1 and a movable mold 2. Part 31 that is substantially perpendicular to the moving direction of the mold
Since a foamed molded product having a part 32 that is substantially parallel to the moving direction of the mold is formed,
When it is attempted to obtain the thickness 41 of the foam layer defined by the moving distance 5 as shown in (b), the substantial foam layer thickness 42 at the portion 32 substantially parallel to the moving direction of the mold is It becomes thinner than the foam layer thickness 41 perpendicular to the moving direction of the mold. Therefore, when the conventional mold as shown in FIG. 5 is used, there is a problem that the thickness of the foam layer varies depending on the part, and it has been a problem to make the thickness of the foam layer uniform. The present invention has been made in view of the above-mentioned conventional problems, and provides a mold-expansion injection foam molding mold capable of obtaining a mold-expansion injection foam molding having a complicated shape having a uniform foam layer thickness. The purpose is to do.

[0004]

In order to solve the above-mentioned conventional problems, in the present invention, in a mold for expanding injection foam molding including a movable mold and a fixed mold, a part of the movable part of the mold has a plurality of parts. A split mold member is formed, and the split mold member is sequentially moved in the mold opening direction in accordance with the mold opening operation at the time of forming the foam layer to solve the problem by uniformly controlling the thickness of the foam layer. It is intended to obtain a resin molded product integrated with a skin foam layer having a thickness.

[0005]

According to the first aspect of the invention, in a mold expanding injection foam molding die comprising a movable die and a fixed die connected to the injection port of the injection molding machine, the movable die is a portion substantially perpendicular to the die moving direction. And a plurality of split mold members that form a portion approximately parallel to the mold moving direction, and the split mold members sequentially move in the mold opening direction with the mold opening operation when forming the foam layer. Therefore, it is possible to obtain an injection foam molded article having a uniform thickness of the foam layer. Further, in claim 2, the plurality of split mold members are used for forming a foam layer on a surface substantially parallel to the mold moving direction, and the split mold members are far from a surface substantially perpendicular to the mold moving direction. Since the moving distance is increased as the split mold is used, the thickness of the foam layer does not become thin even in the foam-molded portion substantially parallel to the mold moving direction, and a uniform injection foam-molded body can be obtained as a whole. Further, according to a third aspect, among the plurality of split mold members, the split mold member having the longest distance from the surface substantially perpendicular to the mold moving direction is fixed to the movable mold plate, and each split mold member is foamed. Since the structures are connected so that they can be sequentially moved in the mold opening direction during the mold opening operation during layer formation, the mold moving direction first along with the mold opening operation during foam layer formation, Since the split mold members that are the farthest from the nearly vertical plane can move, and the split mold members that are connected to this can move sequentially, even the most remote part from the nearly vertical plane can be moved to the near vertical plane. It is possible to secure the same thickness of the foamed layer as that of the solid portion. Further, by connecting the plurality of split mold members by combining the key with the groove, it is possible to reliably move each split mold member.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below according to the embodiments. FIG. 1 shows an embodiment of the present invention, in which a mold is enlarged to obtain a skin-integrated foamed molded product having a “U” -shaped cross-sectional shape as shown in an automobile glove box lid (FIG. 4). It is sectional drawing of the metal mold | die for foam injection molding. The same components as those described in the related art will be described with the same reference numerals.

The mold of this embodiment is composed of a fixed mold 1 and a movable mold 2. The movable mold 2 has a general member 21 corresponding to a portion 31 which is substantially perpendicular to the moving direction of the mold, and the mold. Of a plurality of split mold members 221 to 226 corresponding to a portion 32 substantially parallel to the moving direction of the mold, and a split mold member 221 having the longest distance from a plane substantially perpendicular to the mold moving direction. And a movable die plate 23 that is fixed.

Next, the operation of this mold will be described.
FIG. 1 (a) shows a state in which the mold is closed, and when a resin containing a foaming agent is injected into the cavity 3 in this state, the resin contacting the mold is rapidly cooled, so that a skin without a foamed portion, That is, a skin layer is formed. Next, when the mold opening operation is started, first, the split mold member 221 that is fixed to the movable mold plate 23 and is at the farthest distance from the portion 31 that is substantially perpendicular to the moving direction of the mold starts to move. Next, the adjacent split mold member 22 connected to this split mold member 221.
2, and then further moving to 223, 224, 225 and 226 to form a foam layer corresponding to a portion 32 substantially parallel to the opening / closing direction of the mold, as shown in FIG. 1 (b). A void 4 is formed for this purpose. Here, the moving distance of each of the split mold members 221 to 226 of the split mold 22 is largest in the split mold member 221 farthest from the part 31, and then in the order of 222, 223, 224, 225, 226. Therefore, the mold surface on the movable side can be made smooth, and deformation and breakage of the skin layer can be suppressed.

Split mold members 221 to 22 of the sequential split mold 22
After opening 6, the general part member 21 of the movable die 2 which finally forms the general part has a gap 4 with a thickness 42 for forming a foam layer.
It is possible to obtain an injection-molded article having a foam layer thickness that is substantially uniform as a whole by moving by a distance corresponding to a thickness 41 that is substantially equal to.

Disassembling the plurality of split mold members 221 to 226,
The fitting can be performed, for example, by a combination of the key 6 and the groove 7 as shown in FIG. 2, but is not limited to this. Divided mold members 221 to 2 by the key 6 and the groove 7.
FIG. 3 shows a schematic diagram of the operation of sequentially opening 26. In order to reliably move the split mold members 221-226, a plurality of keys 6 and grooves 7 can be used between the same members. In addition, in order to accurately position the components that make up the mold, the guide pin 24
It is effective to use additional devices such as. Further split mold member 2
When the rubbing area of 21 to 226 is large and the sliding resistance is large, it is possible to use a bearing or the like. It is also possible to use a differential plate to make the operation of the general member 21 more stable.

In the present embodiment, the mold for expanding the foam injection molding to obtain the skin-integrated foam-molded article having a "U" -shaped cross-sectional shape has been described. It is also possible as a mold for mold expansion foam injection molding for obtaining a skin-integrated foam molded product. In this case, the plurality of split mold members 221 to 226 in FIG. 1 have a cylindrical shape.

[0012]

As described above, according to the present invention,
In the mold expansion injection foam molding die that has a structure that is composed of a movable die and a fixed die that are connected to the injection port of the injection molding machine, the movable die has a portion that forms a portion that is substantially perpendicular to the die movement direction, and the die movement. Since the split mold member is configured to move in the mold opening direction in sequence with the mold opening operation when forming the foam layer, the foamed resin product is formed. It is possible to obtain a mold-expanding foam injection-molded article in which the layer thickness is constant regardless of the direction of the part. Further, in the case of a molded product such as an automobile glove box lid as shown in FIG. 4, it is possible to obtain a product having a uniform foam layer thickness on the upper surface and the side surface, that is, a uniform soft feeling, deformation of the skin layer, Since the breakage can be suppressed, the excellent effect of improving the quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an embodiment of the present invention (a).
Is when the mold is open, (b) is when the mold is closed

FIG. 2 is a perspective view illustrating an example of a key and a groove for connecting the split mold members according to the embodiment.

FIG. 3 is a schematic diagram showing an operation of the split mold member according to the embodiment.

FIG. 4 is a perspective view illustrating a glove box lid for an automobile.

FIG. 5 is a diagram illustrating a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed type 2 Movable type 21 General part member 22 Divided type 221-226 Divided type member 23 Movable type plate 24 Guide pin 3 Cavity 31 Approximately vertical part 32 Approximately parallel part 4 Void 41 Foam layer thickness 42 Foam layer thickness 6 key 7 groove

Claims (3)

[Claims] 1. A mold-expansion injection foam molding mold comprising a movable mold and a fixed mold connected to an injection port of an injection molding machine, wherein the movable mold has a portion for forming a portion substantially vertical to a mold moving direction. , A plurality of split mold members that form a portion approximately parallel to the mold moving direction, the split mold members sequentially moving in the mold opening direction in accordance with the mold opening operation at the time of forming the foam layer, and the resin molded product. A mold for expanding injection foam molding, characterized in that the thickness of the foam layer is uniform. 2. The plurality of split mold members are used for forming a foam layer on a surface substantially parallel to the mold movement direction, and the split mold members are far from a surface substantially perpendicular to the mold movement direction. The mold for injection-mold expansion foam molding according to claim 1, wherein a moving distance associated with a mold opening operation is increased as the number of split molds increases. 3. Among the plurality of split mold members, the split mold member having the longest distance from a plane substantially perpendicular to the mold moving direction is fixed to the movable mold plate, and each split mold member is foamed. The mold for injection-mold expansion foam molding according to claim 1 or 2, wherein the molds are connected so as to be sequentially movable in a mold opening direction in accordance with a mold opening operation during layer formation.