JP7173863B2 - injection molded product, injection molding method, injection mold - Google Patents

Description

The present invention relates to injection molded articles, injection molding methods, and injection molds.

For example, automobile interior parts (instrument panels, etc.) are formed by laminating a plurality of types of resin materials having different materials and colors by injection molding (for example, Patent Document 1).

JP-A-2005-111820

When molding a multi-layered injection molded product made of a plurality of types of resin materials as described above, when molding the second layer, the resin material forming the second layer may leak to the first layer side. becomes a problem.

For example, as shown in FIG. 6A, a multi-layered injection-molded product is produced by using an injection mold having an upper mold 110 having a fixed part 111 and a slide mold 112 which is a movable part, and a lower mold 120. molding.

First, by injecting the first resin material into the first cavity 131 formed between the upper mold 110 and the lower mold 120, the first molded layer 101 is molded as shown in FIG. 6(B). . Then, as shown in FIG. 6C, the slide mold 112 is slid upward to form the second cavity 132 between the fixed part 111, the slide mold 112 and the first molding layer 101. As shown in FIG. By injecting the second resin material into the second cavity 132, the second molded layer 102 is molded as shown in FIG. 6(D). Thereby, the injection molded product 100 having the first molding layer 101 and the second molding layer 102 can be molded.

However, in the above molding method, after molding the first molding layer 101 shown in FIG. A gap is created between the bottom surface of the Then, when the second resin material is injected into the second cavity 132 shown in FIG. 6(C), the second injection material leaks into this gap, and as shown in FIG. A leakage portion 102 a is formed in the second molding layer 102 .

As shown in FIG. 7, the appearance of the parting portion between the first molding layer 101 and the second molding layer 102 becomes poor in appearance of the injection-molded product 100 due to the formation of the leakage portion 102a. There was a problem that the quality of appearance of 100 was spoiled.

In particular, instrument panels (hereafter referred to as instrument panels), which are an example of the injection-molded product mentioned above, require both mechanical properties such as strength and rigidity and design qualities such as color, gloss, and texture. In addition to the first molding layer that forms the skeleton, it has a two-layer structure with a second molding layer that has excellent design quality and has a part of the design surface of the instrument panel (for example, the design surface of the upper surface of the instrument panel). However, in the case of such a configuration, the first molded layer and the second molded layer each constitute a part of the design surface of the instrument panel, and the parting part between the two layers is also exposed to the outside to form the design surface of the instrument panel. Since it constitutes a part of the instrument panel, it is difficult to hide the parting part from the appearance, and the appearance quality of the parting part is extremely important in terms of the appearance quality of the entire instrument panel.

In view of such circumstances, it is an object of the present invention to prevent the external appearance of an injection-molded product from being adversely affected by leakage of a resin material during injection molding.

In order to solve the above problems, the present invention provides an injection-molded article integrally having a first molded layer and a second molded layer that are injection-molded from different resin materials, wherein the first molded layer comprises the It is characterized by having a recess formed in a direction opposite to the stacking direction at a position adjacent to the parting part with the second molding layer.

According to the present invention, even if the resin material forming the second molded layer leaks, the leaked portion, particularly the boundary portion between the leaked portion and the first molded layer, is hidden in the recess. It is possible to prevent the external appearance of the injection molded product from being adversely affected.

Further, in order to solve the above problems, the present invention provides an injection molding method for molding an injection-molded article integrally having a first molded layer and a second molded layer made of different resin materials, the method comprising: a step of injection-molding the first molding layer made of a resin material; Forming a cavity facing the mold and the first molding layer, and injecting a second resin material into the cavity to mold the second molding layer, In the step of injecting the second resin material, at a position adjacent to the cavity, a convex portion provided on the one molding die and protruding in a direction opposite to the stacking direction is inserted into a concave portion provided in the first molding layer. It is characterized in that it is arranged in

According to the present invention, the convex portion provided on one of the molds is provided so as to protrude into the concave portion of the first molding layer at a position adjacent to the cavity, thereby forming the one mold and the first molding layer. The direction of the second resin material leaking out between and can be set to the formation direction of the concave portion provided in the first molded layer. Therefore, in terms of the appearance of the injection-molded product, the portion where the second resin material leaks out can be hidden in the recess, and the leakage of the second resin material can prevent the appearance of the injection-molded product from being adversely affected. can be prevented.

Further, the present invention provides an injection molding die for molding an injection-molded article having one molding die and the other molding die and integrally having a first molding layer and a second molding layer made of different resin materials. The one molding die includes a slide mold movable in a direction away from the other molding die, and a convex portion protruding toward the other molding die at a position adjacent to the slide mold. By bringing the one mold and the other mold into contact, the one mold and the other mold face each other, and the first molding layer is formed. The first molded layer forming one cavity and molded by injecting a first resin material into the first cavity has a concave portion formed by a convex portion provided in the first cavity. , disposing the first molding layer at a position corresponding to the first cavity, and separating the slide mold from the other mold in a state in which the convex portion is disposed in the concave portion, It is characterized by forming a second cavity for injection molding of the second molding layer facing the one molding die and the first molding layer.

According to the present invention, it is possible to hide the resin material that leaks out during molding of the second molding layer by the concave portion, thereby preventing the external appearance of the injection-molded product from being adversely affected.

1 is a front view of an injection molded product according to one embodiment of the present invention; FIG. (A) to (D) are cross-sectional views showing the process of molding the injection-molded product. 1 is a perspective view of an injection molded article; FIG. 1 is a perspective view of an instrument panel according to one embodiment of the present invention; FIG. (A) and (B) are cross-sectional views showing other embodiments of an injection mold. (A) to (D) are cross-sectional views showing the process of molding an injection-molded product having a form different from that of the present invention. 1 is a perspective view of an injection-molded article of a form different from that of the present invention; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the injection-molded product 1 of the present embodiment is a multi-layer member in which a first molded layer 11 and a second molded layer 12 are laminated. be.

The first molded layer 11 and the second molded layer 12 are integrally molded by injection molding a first resin material and a second resin material, which are different resin materials, respectively. The first molding layer 11 is provided at a position adjacent to the parting portion X between the second molding layer 12 and in a direction opposite to the direction in which the first molding layer 11 and the second molding layer 12 are stacked (upward in the drawing). It has a groove (recess) 13 . In other words, the groove portion 13 is a portion that is recessed from the surface 11a that is the design surface of the first molding layer 11 (the surface 11a in the stacking direction of the first molding layer 11) formed at a position adjacent to the parting portion X. be. The phrase "the second resin material is different from the first resin material" means, for example, that the two resin materials are different from each other, such as different colors and materials.

The first molded layer 11 has an area larger than that of the second molded layer 12, and a part of the surface of the first molded layer 11 is exposed on the upper side of the figure. The surface on the upper side of the drawing is the design surface that forms the appearance, and not only the upper second molding layer 12 but also a part of the first molding layer 11 constitutes the design surface.

As shown in FIG. 2(A), the first molded layer 11 and the second molded layer 12 that constitute the injection molded product 1 of the present embodiment are integrally molded by an injection mold 20 that is the same mold. be done. The injection mold 20 has an upper mold (one mold) 21 and a lower mold (the other mold) 22 . The lower mold 22 is a movable mold that can move in the vertical direction in the figure. The upper mold 21 has a fixed portion 23 and a slide mold 24 which is a movable portion, and the slide mold 24 is provided so as to be slidable in the vertical direction in the figure. The fixing portion 23 has a convex portion 23a that protrudes toward the lower die 22 side.

A method of molding the injection molded product 1 with the injection mold 20 of the present embodiment will be described below with reference to FIGS. 2(A) to 2(D).

As shown in FIG. 2A, a first cavity 31 is formed between the lower mold 22 and the fixed part 23 and the slide mold 24 in a state where the lower mold 22 is in contact with the upper mold 21. be. At this time, a part of the molding surface of the fixing part 23 protrudes toward the first cavity 31 side compared to the other part due to the protrusion 23 a provided on the fixing part 23 .

By injecting the first resin material into the first cavity 31, the first molding layer 11 is molded as shown in FIG. 2(B). At this time, the groove 13 is formed in the first molding layer 11 by the partial depression of the first cavity 31 formed by the projection 23a.

After molding the first molded layer 11 in the injection mold 20, the slide mold 24 is moved upward in the drawing, as shown in FIG. 2(C). As a result, the second cavity 32 is formed between the fixed portion 23, the slide mold 24, and the upper surface of the first molded layer 11 (in other words, the fixed portion 23, the slide mold 24, and the first molded layer 11 face each other). It is formed.

Then, by injecting the second resin material into the second cavity 32, the second molding layer 12 is molded as shown in FIG. 2(D). Thereby, the injection molded product 1 having the first molded layer 11 and the second molded layer 12 can be molded.

Finally, the lower mold 22 is moved downward in the drawing to open the mold, and the injection molded product 1 is removed from the injection mold 20 . The injection-molded product 1 can be molded by the above steps.

By the way, after molding the first molding layer 11 , the first molding layer 11 is cooled and shrinks, thereby creating a gap between the first molding layer 11 and the fixing portion 23 . In the present embodiment, as shown in FIG. 2(C), the convex portion 23a of the fixing portion 23 is fitted into the groove portion 13 of the first molding layer 11 at a position adjacent to the second cavity 32. As shown in FIG. That is, at a position adjacent to the second cavity 32, the fixed portion 23 provided over the vertical direction of the drawing serves as a wall, and the gap is formed between the surface of the first molding layer 11 in contact with the convex portion 23a and the convex portion. 23a {see part A in FIG. 2(C)}, and it is generated in the vertical direction of the drawing. By injecting the second resin material into the second cavity 32 in this state, the leaked second resin material flows into the gap, and as shown in FIG. A leakage portion 12a extending downward in the figure is formed.

As in the present embodiment, the first molding layer 11 has the groove 13 at a position adjacent to the parting portion X (see FIG. 1) between the second molding layer 12 and the appearance of the injection molded product 1. The portion 12a can be made inconspicuous. That is, as shown in FIG. 2D, the leakage portion 12a is formed along the convex portion 23a, so that the leakage portion 12a is formed in the direction of entering the groove portion 13, as shown in FIG. Thus, in terms of appearance of the injection molded product 1, the leakage portion 12a is hidden in the groove portion 13 and is difficult to see. In particular, since the boundary between the leakage portion 12a and the first molding layer 11 is hidden by the groove portion 13, it is possible to prevent the appearance of the injection molded product 1 from being adversely affected by the leakage portion 12a.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

FIG. 4 shows a perspective view of an entire instrument panel as an example of an injection-molded product molded by the injection molding method of the present invention. The instrument panel 40 shown in FIG. 4 comprises a first molding layer 41 and a second molding layer 42 made of different resin materials. For example, the first molding layer 41 is made of a resin material exhibiting required mechanical properties (strength, rigidity, etc.), and the second molding layer 42 is made of a resin material having a predetermined color, gloss, and texture for the purpose of improving design quality. It is formed of a resin material that can exhibit appearance characteristics such as texture. The first molded layer 41 , the second molded layer 42 , and the parting portion X of both constitute the design surface of the instrument panel 40 .

In the instrument panel 40 of the present embodiment, similarly to the injection-molded product 1 shown in FIG. Even if the second resin material leaks out during molding of 42, the leaked part is hidden by the groove part, and the external appearance of the parting part X can be prevented from being adversely affected.

In the above description, the injection-molded product 1 has two layers, the first molding layer 11 and the second molding layer 12, made of different resin materials. may have.

The “stacking direction” of the grooves 13 provided in the direction opposite to the stacking direction described above means that the second molding layer 12 is stacked on the first molding layer 11 at the position adjacent to the parting part X. It is not necessarily the same as the lamination direction of the entire second molded layer 12 with respect to the first molded layer 11 .

In the above description, the slide mold is provided in the same mold to mold the first molding layer and the second molding layer (see FIG. 2). Alternatively, the second molding layer may be molded using a mold different from that for the first molding layer. Further, as shown in FIG. 5A, an upper mold (one mold) 25 has a first molding portion 25a for molding the first molding layer and a second molding portion 25b for molding the second molding layer. Then, after molding the first molding layer between the first molding part 25a and the lower mold (the other mold) 22, the upper mold 25 slides leftward in the drawing, and the second molding part 25b and the lower mold 22 Alternatively, as shown in FIG. 5B, the first molding layer is formed on one side of the upper mold 26 (one mold). and a second molding surface 262 for molding the second molding layer on the other side. After molding the first molding layer between the first molding surface 261 and the lower mold 22, A configuration in which the upper mold 26 is rotated and the second molding layer is molded between the second molding surface 262 and the lower mold 22 may be employed.

REFERENCE SIGNS LIST 1 injection molded product 11 first molding layer 12 second molding layer 13 groove (recess)
20 injection mold 21 upper mold (one mold)
22 Lower mold (other mold)
23 fixed part 23a convex part 24 slide mold 31 first cavity 32 second cavity X parting part

Claims (3)

An injection-molded article integrally having a first molded layer and a second molded layer that are injection-molded from different resin materials,
The first molding layer has a recess formed in a direction opposite to the stacking direction at a position adjacent to the parting part with the second molding layer ,
An injection molded article , wherein the thickness of the second molding layer is greater than the depth of the recess . An injection molding method for molding an injection molded article integrally having a first molded layer and a second molded layer made of different resin materials,
injection molding the first molding layer made of a first resin material;
In a state in which one molding die and the other molding die are brought into contact with each other and the first molding layer is arranged inside, the slide mold provided in the one molding die slides from the other molding die. By moving in a direction away from each other, a second cavity is formed in which the slide mold and the first molding layer face each other, and a second resin material is injected into the second cavity, thereby performing the second molding. molding the layer;
In the step of injecting a second resin material into the second cavity, a portion adjacent to the slide mold of the one molding die protrudes in a direction opposite to the stacking direction at a position adjacent to the second cavity. The injection molding method, wherein the convex portion abuts on the concave portion provided in the first molding layer. An injection molding die for molding an injection-molded article having one molding die and the other molding die and integrally having a first molding layer and a second molding layer made of different resin materials,
The one mold has a slide mold that is movable in a direction away from the other mold, and a convex portion that protrudes toward the other mold at a position adjacent to the slide mold,
By bringing the one mold and the other mold into contact, the one mold and the other mold face each other to form a first cavity for molding the first molding layer. death,
The first molding layer molded by injecting a first resin material into the first cavity has a concave portion formed by a convex portion disposed in the first cavity,
By disposing the first molding layer at a position corresponding to the first cavity and separating the slide mold from the other molding die in a state in which the convex portion is disposed in the concave portion, the An injection mold characterized by forming a second cavity for injection molding the second molding layer, in which one mold and the first molding layer face each other.

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