JPH10100165A - Production of foamed molded product fitted with core plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To impart uniform foaming density without generating voids in a foamed layer when the thin-walled foamed layer is formed on a core plate and to impart strong joining force between the core plate and the foamed layer. SOLUTION: A mold 7 is opened to fix a core plate 2 having a large number of through-holes to one side of a cavity 11 and the foamable raw soln. 15 dispersed to the other side of the cavity 11 to be injected is spread and filled into the almost whole of the cavity 11 by closing a mold 7 and air interposed between the foamable raw solns. 15 is discharged to the outside through the through-holes. Thereafter, the thin-walled foamed layer 3 is formed on the core plate 2 and a part of the foamed layer 3 is allowed to protrude to the rear of the core plate 2 through the through-holes to form an anchor part 6. By the anchoring effect of the anchor part 6, the joining force of the core plate 2 and the foamed layer 3 is reinforced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a foamed product with a core plate having a foam layer formed on the surface of a core plate, and more particularly to a method of opening a mold and installing a core plate on one side of a cavity. Then, after injecting the foaming stock solution into the cavity, the mold is closed, and the foaming stock solution is foamed to form a continuous foamed layer on the surface of the core board. About.

[0002]

2. Description of the Related Art A method for producing such a foamed molded product with a core plate is already known, for example, as disclosed in Japanese Patent Application Laid-Open No. 7-1476.

[0003]

In the conventional method of manufacturing a foam molded article with a core plate, when a molding die is opened and a foaming undiluted solution is injected into the cavity, the injection is concentrated in one location of the cavity and then the molding die is opened. Is closed and the molding solution is filled in the entire cavity by the foaming pressure.

In such a method in which the filling of the cavity of the molding stock solution depends only on the foaming pressure of the stock solution, when a thin foamed layer is to be formed, a large flow resistance in the cavity of the highly viscous foaming stock solution is required. As a result, poor filling easily occurs and voids (cavities) are easily formed in the molded product. Therefore, in order to avoid a defective filling, it is necessary to make a sufficient space between the cavities, and accordingly, the amount of the foaming liquid used increases, and the foamed layer becomes thicker than necessary, resulting in high cost. Become.

The present invention has been made in view of such circumstances, and provides a method of manufacturing a foam molded article with a core plate, which can surely form a thin foam layer on a core plate without generating voids. The purpose is to provide.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a process of opening a mold and installing a core plate having a plurality of through holes communicating between the front and back sides of one side of the cavity. A step of dispersing and injecting the foaming undiluted solution on the other side, a step of compressing and expanding the foaming undiluted solution by closing the mold, filling substantially the entire area of the cavity with a layer, and foaming the foaming undiluted solution to form a core plate. The first feature is that a continuous foaming layer is formed on the surface, and a step of forming an anchor portion by sequentially protruding a part of the foaming layer from the through hole toward the back side of the core plate. I do.

[0007] In addition to the above-mentioned features, the present invention further comprises a plurality of recesses on the inner surface of the mold opposite to the back surface of the core plate, the recesses being larger in diameter than the through holes and allowing the foam layer to protrude therefrom. The second feature is that

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

First, referring to FIGS. 1 and 2, an automobile instrument panel 1 which is a foam molded article with a core plate manufactured according to the present invention will be described. The instrument panel 1 is formed by sequentially laminating a core plate 2 made of injection-molded synthetic resin, a thin foam layer 3 made of urethane foam, and a slash-molded synthetic resin skin 4. Gives the skin 4 a soft feeling.
The core plate 2 is provided with a large number of through-holes 5 communicating with the front and back surfaces thereof, and a part of the foam layer 3 protrudes to the back side of the core plate 2 through these through-holes 5 to form an anchor portion 6. Is formed. In the illustrated example, the through hole 5 is a tapered hole having a larger diameter toward the back surface of the core plate 2, that is, the side opposite to the foam layer 3, for the reason of molding.

Next, a mold 7 for manufacturing the instrument panel 1 will be described with reference to FIGS. The molding die 7 includes a fixed die 8 serving as a female die and a pivot 1
The movable mold 9 is constituted by a male mold which is connected to be openable and closable in the up-down direction via a movable mold 9.
A cavity 11 corresponding to the shape of the instrument panel 1 is defined between nine. A hot water heater 12 for heating both dies 8, 9 is embedded so as to surround the cavity 11. The movable die 9 has a large number of through holes 5 in the core plate 2.
Are provided at the corresponding positions.

Now, a method of manufacturing the instrument panel 1 will be described. First, as shown in FIG. 3, the skin 4 is placed on the inner surface of the movable mold 9 such that the surplus peripheral edge 4 a extends out of the cavity 11.

Next, as shown in FIG. 4, an undiluted foaming solution 15 is dispersed and injected over the entire surface of the cavity 11 with a plurality of injection nozzles 14 on the skin 4.

Then, as shown in FIG. 5, when the movable mold 9 is closed, the foaming stock solution 15 dispersed on the skin 4 is compressed and extended between the two molds 8 and 9. At this time, the next foaming stock solution 1
The air interposed between the core plate 2 and the core plate 2
And is discharged outside through a minute gap between the opposing surfaces of the movable mold 9. As a result, the foamed undiluted solution 1 due to the residual air
5 can be avoided.

When the movable mold 9 is completely closed, as shown in FIG.
Is spread over substantially the entire area of the cavity 11 to be filled, and the surplus peripheral edge portion 4a of the skin is sandwiched between the joining surfaces of the two dies 8, 9.

The closed state of the mold is maintained for a predetermined time (for example, 2-3 times).
When the two types 8 and 9 heated by the heater 12 hold, the filling and foaming stock solution 15 foams to completely fill the gap between the core plate 2 and the skin 4 to form the foamed layer 3. A part of the foam layer 3 is formed by a large number of through holes 5 of the core plate 2.
Are formed so as to protrude into a large number of concave portions 13 of the movable mold 9 to form a large number of anchor portions 6. Then, the foam layer 3 and the anchor portion 6 are solidified, and the foam layer 3 is joined to the skin 4 and the core plate 2.

After the elapse of the predetermined time, as shown in FIG.
The movable mold 9 is opened, the molded product is taken out, and the molded product is tempered in an annealing furnace for 4 to 5 hours. After that, through a trimming process, the desired instrument panel 1
Can be obtained.

By the way, since the foaming undiluted solution 15 is already spread over almost the entire area of the cavity 11 by closing the mold before the foaming is started, and is in a filled state, each part starts foaming at the same time during the foaming. The unevenness of the foaming density of each part of the foamed layer 3 can be eliminated, and the foamed layer 3 can be made thinner.

According to the test, the thickness of the foamed layer 3 is 8 to 10 mm in the conventional method, whereas the thickness of the foamed layer 3 is 1 to 4 mm in the method of the present invention. A foam layer 3 having a stable density and no voids can be obtained.

The provision of the thin foamed layer 3 in this way means that the solidification time is also shortened, and the timing of opening the movable mold 9 and removing the molded product can be hastened.

FIG. 9 shows the relationship between the foaming rate of the foamed layer 3 and the time. As is apparent from FIG. 9, the foaming of the foamed layer 3 proceeds slightly after being removed from the mold 7. However, in the thin foam layer 3, the change in thickness and shape due to the progress of foaming as described above can be extremely suppressed, and the quality is stabilized.

In addition, the thickness of the foam layer 3 can be reduced by the foaming solution 1
5 will result in a reduced injection volume,
Therefore, it can greatly contribute to cost reduction.

Further, since a large number of anchor portions 6 formed on the back side of the core plate 2 are integrally connected to the foamed layer 3,
By these anchoring effects, the bonding strength between the foam layer 3 and the core plate 2 can be enhanced. In particular, since the anchor portion 6 is formed in the enlarged portion having a larger diameter than the through hole 5 by the concave portion 13 of the movable die 9, the anchoring effect can be surely exhibited.

The present invention is not limited to the above embodiment, and various design changes can be made without departing from the gist of the present invention. For example, the through hole 5 of the core plate 2 may be a tapered hole whose diameter increases toward the surface of the core plate 2. Further, when the mold is closed, a part of the foaming undiluted solution 15 can be made to slightly protrude into the through hole 5 side of the core plate 2. Further, the skin 4 can be omitted.

[0024]

As described above, according to the first aspect of the present invention, a mold is opened, a core plate having a large number of through holes is set on one side of a cavity, and the core plate is dispersed on the other side of the cavity. The injected foaming stock solution is extended and filled over substantially the entire cavity by closing the mold, and the air intervening between the foaming stock solutions is discharged to the outside through the through-holes. By forming a layer, a part of the foam layer is protruded to the back side of the core plate through the through hole, and is used as an anchor portion, so that a foamed product with a core plate having a thin foam layer is provided at low cost. can do. In addition, the foamed layer can be of high quality with uniform foaming density in each part and no voids. Further, the bonding strength between the foam layer and the core plate can be enhanced by the anchoring effect of the anchor portion, so that it is not necessary to apply an adhesive between the foam layer and the core plate.

According to a second feature of the present invention, a plurality of recesses are formed on the inner surface of the mold opposite to the back surface of the core plate, the plurality of recesses being larger in diameter than the through holes and allowing the foam layer to protrude therefrom. Therefore, the anchor portion having a high anchoring effect can be reliably connected to the foam layer by these concave portions.

[Brief description of the drawings]

FIG. 1 is a perspective view of an automotive instrument panel manufactured by the method of the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a diagram illustrating the formation of the instrument panel.
Sectional view showing a state where a skin and a core plate are set on a fixed type and a movable type.

FIG. 4 is a cross-sectional view showing a state where an undiluted foaming solution is injected.

FIG. 5 is a cross-sectional view showing a process of compressing a foaming stock solution by a movable mold.

FIG. 6 is a sectional view showing a movable mold in a completely closed state.

FIG. 7 is a sectional view showing a foaming state of a foaming stock solution.

FIG. 8 is a sectional view showing a state in which a molded product is taken out.

FIG. 9 is a diagram showing the relationship between foaming rate and time.

[Explanation of symbols]

 1 ··· Molded product (instrument panel) 2 ··· Core plate 3 ··· Foam layer 5 ··· Through hole 6 ··· Anchor 7 ··· Mold 11・ Cavity 13 ・ ・ ・ Recess 15 ・ ・ ・ Undiluted foaming solution

Continuation of the front page (72) Inventor Toyoharu Yanagimoto 2-45, Yoshinodai, Kawagoe-shi, Saitama Pref.

Claims (2)

[Claims] 1. A mold (7) is opened to open a cavity (1).
1) a step of installing a core plate (2) having a plurality of through holes (5) communicating between the front and back sides on one side, and a step of dispersing and injecting a foaming solution (15) into the other side of the cavity (11); A step of compressing and expanding the foaming stock solution (15) by closing the mold (7) to fill substantially the entire area of the cavity (11) in a layer form; and foaming the stock foaming solution (15) to form a core plate (2). ), A continuous foamed layer (3) is formed on the surface, and a part of the foamed layer (3) is protruded from the through hole (5) toward the back side of the core plate (2) to form an anchor portion. (6) A method for producing a foamed molded product with a core plate, which comprises sequentially performing the step of forming (6). 2. A foaming layer (3) formed from an inner surface of a molding die (7) having a diameter larger than that of the through hole (5) and facing the back surface of the core plate (2). A) forming a plurality of recesses (13) that allow overhang of (1).