JP2001277276A - Core mold and mold used in manufacturing in-mold foamed molded object with skin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a core mold and a mold both of which are used in manufacturing an in-mold foamed molded object with a skin, capable of being preheated in a mold open state and capable of shortening a molding cycle. SOLUTION: A skin material 22 is arranged in one core mold 1 among two core molds 1,21 respectively attached to a female mold A and a male mold B both of which constitute a mold C and, after mold clamping, foam molding is performed in this mold 24 to manufacture the in-mold foamed molded object 2 with the skin wherein an in-mold foamed molded object 28 and the skin material 22 are integrally fused. In the core mold l used in this manufacturing method, at least one chamber 3 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a middle mold and a mold used for producing a foamed molded article with a skin used for, for example, interior materials for automobiles.

[0002]

2. Description of the Related Art Conventionally, a thermoplastic resin skin material has been arranged in one of two middle dies attached to two molds constituting a molding die, and the mold has been clamped. A so-called simultaneous integral molding in which a foamed molded article in a mold and a thermoplastic resin skin material are fused and integrated by foam molding is known.

In each of the two molds, a mold chamber to which a steam valve or the like is connected is provided, and a middle mold having a predetermined shape is also attached. A plurality of air holes are formed in the middle mold on which the thermoplastic resin skin material is arranged, and these air holes are connected to the pressure reducing valves by individual pipes for vacuum forming of the thermoplastic resin skin material and the like. I have. A plurality of steam holes communicating with the mold chamber are formed in the other middle mold.

At the time of foam molding, steam is supplied from a steam hole of the other middle mold into the mold to heat-foam the foam beads filled in the mold.
In this case, before the thermoplastic resin skin material is disposed, steam is supplied into the mold chamber to preheat one of the middle dies before the thermoplastic resin skin material is disposed in order to efficiently perform foam molding by preheating the thermoplastic resin skin material. I often do that.

[0005]

However, since the mold chamber is pressurized at a high pressure by the supply of steam, such preheating is performed in a clamped state to protect the mold. Therefore, there is a problem that the molding cycle of the in-mold foam molded article with the skin is relatively long.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is intended to provide a middle mold and a mold used for producing an in-mold foam molded article with a skin that can be preheated while the mold is opened and can shorten the molding cycle. The purpose is to provide.

[0007]

In order to achieve the above-mentioned object, a middle mold according to claim 1 is provided in one of two middle molds respectively attached to two molds constituting a molding die.
After arranging the skin material and closing the mold, by foam-forming in this mold, the in-mold foam-formed body to be formed is fused and integrated with the skin material to produce an in-mold foam-molded body with a skin. In the middle sized mold to be used, at least one chamber is provided in the one middle sized mold.

According to a second aspect of the present invention, at least one heating chamber and one cooling chamber are provided in the one middle mold.

In a third aspect, a plurality of ventilation holes are formed in the one middle size.

According to a fourth aspect of the present invention, the vent hole is not communicated with the chamber and communicates with a mold chamber provided in a mold to which the one middle mold is attached.

[0011] The medium mold according to a fifth aspect of the present invention comprises a front mold constituting the design surface of the one medium mold, and at least one back plate attached to the back of the front mold so as to form the chamber.

According to a sixth aspect of the present invention, the surface mold and the back plate are connected to each other through at least one hollow joint pillar connecting the ventilation hole formed in the surface mold and the chamber hole formed in the back plate. It is integrated.

According to a seventh aspect of the present invention, there is provided a mold to which the middle mold according to any one of the first to sixth aspects is attached.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 to 5, a middle mold 1 according to this embodiment is used for manufacturing an in-mold foam molded article 2 with a skin, and has a chamber 3 provided therein.

As shown in FIGS. 1 and 2, for example, the middle mold 1 has a front mold 4 forming a design surface 4a, and a back mold attached to the back 4b of the front mold 4 so that the chamber 3 is formed. It is composed of a plate 5 and is integrated via a plurality of hollow joint pillars 8 connecting a ventilation hole 6 formed in the surface mold 4 and a chamber hole 7 formed in the back plate 5.

In this embodiment, the surface mold 4 and the back plate 5 are all formed with a concave cross section. However, the present invention is not limited to this. It can be changed as appropriate according to the shape and the like. Also,
The design surface 4a may be provided with design pattern irregularities such as leather grain, if necessary.

The hollow joint pillar 8 is formed, for example, in a tubular shape, and protrudes from the rear surface 4 b of the front mold 4 in accordance with the position of the ventilation hole 6. The chamber holes 7 of the back plate 5 are formed in accordance with the positions of the ventilation holes 6 and the hollow joint pillars 8. A female screw is formed on the inner peripheral surface 8a of the hollow joint pillar 8, and an end of the hollow joint pillar 8 and a head 9a of a bolt 9 inserted into the chamber hole 7 and screwed to the female screw. The back plate 5 can be screwed in between.

Since a skin material to be the skin of the foamed molded article 2 with a skin is disposed on the design surface 4a, the bolt 9 can be screwed on the back plate 5 side as in this embodiment. It is desirable to keep. In this case, the hollow joint pillar 8
May be fixed on the back surface 4b of the front mold 4 by fixing a separate component by welding or bonding, or by integrating it by casting or the like.
In the case where the can be directly screwed to the surface mold 4, for example, it may be provided on the back plate 5 in the same manner. The bolt 9 may be formed with a communication hole 11 for communicating the internal space 10 of the hollow joint pillar 8 and the ventilation hole 6 of the surface mold 4 with the outside of the back plate 5. Further, the back plate 5 is not limited to the one formed integrally, and may be dividable into a plurality at a predetermined portion.

As shown in FIG. 1, for example, the middle mold 1 thus constituted is composed of a female mold (mold) A and a male mold (mold) B which can be closed and opened in the horizontal direction. Mold C
The female die A is mounted on the female die A, and the male die B is also mounted with a middle die 21 having, for example, a convex cross section.

In order to manufacture the in-mold foam molded article 2 with a skin, first, as shown in FIGS. 1 and 3, a skin material 22 is arranged on one middle mold 1 attached to a female mold A.

Here, a steam valve A1, a cooling water valve A2, and a drain valve A3 are connected to one of the chambers 3 of the middle mold 1. A mold chamber A5 is provided in the female mold A, and a pressure reducing valve A4 is connected to the mold chamber A5. The plurality of ventilation holes 6 formed in the surface mold 4
Communicates with the mold chamber A5 through the internal space 10 of the hollow joint pillar 8 and the communication hole 11 of the bolt 9.

A mold chamber B5 is also provided in the male mold B, and a steam valve B1 and a drain valve B3 are connected to the mold chamber B5. Also, the mold chamber B5
A cooling water valve B <b> 2 is connected to the cooling pipe 23 disposed in the inside, so that cooling water can be jetted from a nozzle (not shown) provided at a predetermined position of the cooling pipe 23. For male type B,
A feeder 26 for filling the foaming beads 25 into the mold 24 is provided. A plurality of steam holes 27 communicating with the mold chamber B5 are formed in the other middle mold 21 attached to the male mold B.

Examples of the skin material 22 include a thermoplastic resin sheet made of a vinyl chloride resin or an olefin resin such as a polyethylene resin or a polypropylene resin. In addition, since the skin material 22 becomes the skin of the in-mold foam molded article 2 with the skin, the skin material 22 may be colored in a desired color in advance with a coloring agent or the like according to its use.

In order to arrange the skin material 22 on one of the middle molds 1, it is possible to use another mold or the like which has been formed in advance by vacuum molding or the like so as to conform to the design surface 4 a of the middle mold 1. Although it is good, it is desirable to perform thermoforming such as vacuum forming in the middle mold 1 in order to save the trouble. In addition, as the thermoforming, in addition to the vacuum forming, for example, air pressure forming, vacuum / pressure forming, or the like may be adopted.

In order to perform thermoforming with the middle mold 1, the skin material 22 is brought into contact with the middle mold 1 in a state where the skin material 22 has been heated and softened in advance, and then the pressure reducing valve A 4 is opened to place the skin material 22 between the middle mold 1 and the skin material 22. The skin material 22 may be brought into close contact with the design surface 4a of the middle die 1 by exhausting the air. In this case, the design surface 4a may be preheated to a predetermined temperature in order to reduce the temperature drop of the softened skin material 22 and perform thermoforming efficiently, but this preheating is performed by opening the steam valve A1. What is necessary is just to supply steam S into the chamber 3 or the like.

At this time, in order to prevent the temperature of the skin material 22 from being lowered during the thermoforming, the heating may be continued during the thermoforming,
Alternatively, multi-stage heating or the like in which the set temperature is appropriately changed from the initial preheating temperature may be performed. When the skin material 22 is made of an olefin-based resin, the temperature during the thermoforming is set to 60.
The temperature is desirably in the range of from 150 to 150C, preferably from 60 to 130C, more preferably from 70 to 120C. 60
When the temperature is lower than ℃, the skin material 22 does not soften much,
If the temperature is higher than 150 ° C., it is not desirable because it is too soft.

The heating medium is not limited to the steam S, but may be made to supply, for example, hot oil or hot water. In order to cool the design surface 4a at the time of removing the mold, the cooling water valve A2 is opened and the cooling water may be supplied or injected into the chamber 3, but other cooling media such as oil and solution can be supplied. It may be set as.

The number of the chambers 3 is not particularly limited. A plurality of the chambers 3 may be provided as necessary, and the design surface 4a may be heated and cooled for each part.
Here, the heating chamber 3 to which the steam valve A1 and the like are connected.
When the cooling chamber 3 to which the cooling water valve A2 and the like are connected is separately provided, there is an advantage that even when the composition of the heating medium and the composition of the cooling medium are different, each can be recycled.

As described above, if at least one chamber 3 is provided in the middle mold 1, since the mold chamber A5 is not pressurized, the middle mold 1 can be preheated even when the mold is opened. Therefore, there is an advantage that the molding cycle of the in-mold foam molded article 2 with the skin can be shortened.

If a plurality of ventilation holes 6 are formed in the middle mold 1, there is an advantage that the thermoforming of the skin material 22 can be easily performed with the middle mold 1. If these ventilation holes 6 are not communicated with the chamber 3 and are communicated with the mold chamber A5, a drain or the like does not adhere to the skin material 22 and molding defects do not occur. There is an advantage that it is only necessary to connect the pressure reducing valve A4 to the mold chamber A5 without individually piping.

Further, if the middle mold 1 is composed of the front mold 4 and at least one back plate 5, there is an advantage that the manufacture of the middle mold 1 having the chamber 3 therein is simple. If the surface mold 4 and the back plate 5 are integrated via the hollow joint pillar 8 described above, the joint portion and the decompression line can be shared, and there is an advantage that the cost can be reduced. The number, shape, and the like of such hollow joint pillars 8 are not particularly limited, and there may be a vent hole 6 in which the hollow joint pillar 8 is not provided. Since connection is necessary, it is desirable to integrate all the pressure reduction lines via the hollow joint pillar 8. Further, there may be a hollow joint pillar 8 having no vent hole 6 or other joint members.

After the skin material 22 is arranged on the middle mold 1, as shown in FIG. 3, the foamed beads 25 are filled from the feeder 26 into the mold 24 by clamping. At this time, the mold may be clamped in a state where a gap is slightly opened (a cracking state) in order to easily release the air in the mold 24.

As the expanded beads 25, various kinds of conventionally known beads made of an olefin resin or a styrene resin can be used. When the foaming ratio at the time of foaming the foam beads 25 in the mold is smaller than 3 times, the cushioning property and the like of the formed foam in the mold tends to decrease. Since the molded article tends to be too soft and the strength or the like tends to decrease, the ratio is desirably 3 to 60 times, preferably 5 to 50 times, more preferably 8 to 45 times, and particularly preferably 10 to 35 times. As such foam beads 25, for example, Eperan PP (trade name, manufactured by Kaneka Chemical Industry Co., Ltd.) or the like can be preferably used.

Next, as shown in FIG. 4, the steam valve B1 connected to the mold chamber B5 of the male mold B is opened to open the steam S
Is supplied from the steam hole 27 of the other middle mold 21 to the inside 24 of the molding die, and the foam beads 25 are heated and foamed. In addition, at the time of this heating and foaming, in order to prevent the occurrence of defective fusion, if necessary, pre-heating with steam S at a temperature lower than the temperature at which they are fused together, or steaming for maintaining the state for a predetermined time,
Further, after the steaming, the pressure reducing valve B4 may be opened, and the drain 24 may be removed in advance by evacuation of the inside of the mold 24 through the steam hole 27.

After that, if necessary, the mold is cooled, the mold is opened, and the mold is released, so that the in-mold foam molded article 28 formed by in-mold foaming of the expanded beads 25 and the surface of the in-mold foam molded article 28 are formed. Ear 22 comprising fusion-bonded skin material 22
Since the in-mold foam molded article 2a having a is obtained, if the ear 22a is cut off as necessary, the in-mold foam molded article 2 shown in FIG. 5 can be obtained.

As described above, in this embodiment, the case where the chamber 3 is provided in one middle mold 1 attached to the female mold A has been described. However, the present invention is not limited to this, and the other is attached to the male mold B. In the case where the skin material 22 is disposed on the middle mold 21 or the like, the chamber 3 may be provided in the other middle mold 21. In this case, the other middle mold 21 can have the same configuration as the one middle mold 1 described above. The molding die C may be capable of clamping and opening the mold not only in the horizontal direction but also in the vertical direction and the like.

[0037]

As described above, according to the first embodiment of the present invention, since at least one chamber is provided inside, the mold chamber of the mold to which this middle mold is attached is not pressurized. . Therefore, there is an advantage that the middle mold can be preheated even with the mold opened, and the molding cycle of the in-mold foam molded article with the skin can be shortened.

According to the second aspect of the present invention, since one heating chamber and one cooling chamber are provided, even when the composition of the heating medium and the composition of the cooling medium are different, each can be recycled. is there.

According to the third aspect of the present invention, since a plurality of ventilation holes are formed, there is an advantage that the thermoforming of the skin material can be easily performed by the middle type.

According to the fourth aspect of the present invention, the vent hole is not in communication with the chamber and communicates with the mold chamber.
There is an advantage that a drain or the like does not adhere to the skin material and molding defects do not occur, and it is only necessary to connect the pressure reducing valve to the mold chamber without separately piping the vent holes.

According to the medium mold of the fifth aspect, since it is composed of the surface mold and at least one back plate, there is an advantage that the manufacture is simple.

According to the sixth aspect of the present invention, since the surface mold and the back plate are integrated via the hollow joint pillar,
There is an advantage that the joint portion and the pressure reducing line can be shared, and the cost can be reduced.

According to the mold of the seventh aspect, since the above-described middle mold is attached, the same effects as those of the first to sixth aspects are obtained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a state in which a middle mold according to an embodiment is attached to a female mold.

FIG. 2 is an enlarged sectional view of a main part of a middle-sized hollow joint pillar of FIG. 1;

FIG. 3 is a schematic cross-sectional view showing a state in which foamed beads are filled in a mold.

FIG. 4 is a sectional view showing a state of foam molding.

FIG. 5 is a sectional view of an in-mold foam molded article with a skin.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 One middle size 2 In-mold foaming product with skin 3 Chamber 4 Front surface type 4a Design surface 4b Back surface 5 Back plate 6 Vent hole 7 Chamber hole 8 Hollow joint pillar A Female mold (mold) A5 Mold chamber B Male mold ( Mold) B5 Mold chamber C Mold 21 Other medium 22 Skin material 24 Inside mold 28 Inside foam molded body

Claims (7)

[Claims] 1. A skin material is placed in one of two middle dies attached to two molds constituting a molding die, and after clamping the mold, foam molding is performed in the molding die. In a middle mold used for manufacturing a molded foam molded article with a skin in which the formed molded foam article and the skin material are fused and integrated, at least one chamber is provided in the one middle mold. Medium size used for the production of foamed molded products with a skin inside. 2. The middle mold used for producing a skin-molded foam molded article according to claim 1, wherein at least one heating chamber and one cooling chamber are provided in said one middle mold. 3. The middle mold used for producing a foamed molded article with a skin according to claim 1 or 2, wherein a plurality of air holes are formed in said one middle mold. 4. The method of claim 3, wherein the vent hole is not in communication with the chamber and communicates with a mold chamber provided in a mold to which the one middle mold is attached. Medium to use for. 5. A surface mold comprising the one medium-sized design surface, and at least one back plate attached to a back surface of the front mold so that the chamber is formed. A medium mold for use in manufacturing the foamed molded article with a skin according to any of the above. 6. The surface mold and the back plate are integrated with each other via at least one hollow joint pillar connecting the ventilation hole formed in the surface mold and the chamber hole formed in the back plate. 5. A middle mold used for producing the in-mold foam molded article with a skin according to 5. 7. A mold for use in the production of an in-mold foam molded article with a skin to which the middle mold according to claim 1 is attached.