JP3485142B2 - Method for producing molded article integrally foamed with foaming mold and insert - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shape in which a foam stock solution, which is a mixture of at least two kinds of raw material liquids that foam and harden when mixed, is foamed and hardened to form a side wall whose peripheral edge rises like a tray. Regarding the method for producing a foamed mold used for foam-molding into a molded body and a molded body in which the peripheral edge integrally foam-molded using the molding die stands up like a tray and is a side wall, The expansion / shrinkable seal tube arranged at the position corresponding to the upper end of the side wall of the molded body of the molding die is expanded to seal the upper end of the rising portion of the cavity, and the foaming from the mating surface of the upper die and the lower die is performed. A foaming mold that prevents the foaming stock solution from leaking out, a foaming body with a raised peripheral edge to form a side wall, and an insert that is arranged on the concave surface of the foaming material and is lined. A method for producing a foamed molded product to froth forming.

[0002]

2. Description of the Related Art In a cavity of a molding die which can be divided into a lower mold and an upper mold, a raw foam material mixture, for example, urethane, in which at least two kinds of raw material liquids which are foamed and hardened when mixed is mixed, is cast and foamed and hardened. While molding, the uncured foaming undiluted solution infiltrates into the mating surfaces of the upper and lower molds, creating spews like fins surrounding the foamed molding, or the foam that has penetrated into the mating surface. The undiluted solution leaks out of the molding die, resulting in waste of material or sticking to the outer surface of the molding die. In order to prevent the undiluted solution of the foam from entering the mating surface, Japanese Utility Model Laid-Open No. 60-14914 discloses that an annular groove is provided in one of the parts that rub against each other when the mating surfaces of the upper mold and the lower mold are opened and closed, and the groove has a cross section. The U-shaped thermosetting resin seal block is embedded so that the recess opens at the mating surface, and the elastic seal block is embedded in the recess of the seal block so as to project from the mating surface, and the mating surface is sealed. A molding die is described.

In general, a foamed molded article whose outer edge is made of polyurethane and rises like a tray to form a side wall is often used by being attached to a structure composed of a plurality of members. In many cases, when mounting to the structure using bolts, screws, etc., the foamed molded body has low rigidity and cannot be directly mounted by bolts, screws, etc., so the plate-shaped object is lined with an insert molded in the same shape as the foamed molded body. Then, it is attached to the structure with bolts, vist, etc. through the insert. Foam molded product lined with inserts,
For example, an instrument panel for accommodating automobile instruments, a so-called instrument panel, is manufactured by integrally foam-molding an insert and a semi-hard or hard urethane in the following manner using a foam molding die whose cross section is shown in FIG. It had been. That is,
As shown in FIG. 4, the foam molding die 1 can be divided into an upper die 3 and a lower die 2, and a lower die recess 4 for forming a cavity 10 is provided on the upper surface of the lower die 2 so that the upper die 3 has An upper die convex portion 9 having a cross section smaller than the lower die concave portion 4 is provided in a protruding manner, and a cavity 10 having a raised peripheral edge is defined between the lower die concave portion 4 and the upper die convex portion 9. A sealing material 14 made of polyurethane foam is preliminarily attached to an insert 13 molded in a shape substantially the same as the surface shape of the upper mold convex portion 9 of the foam molding die 1 at a position corresponding to the upper end of the foam molding body. The insert 13 around which 14 is attached is temporarily fixed to the upper die convex portion 9. The upper mold 3 having the insert 13 temporarily fixed thereto is placed at a predetermined position of the lower mold 2 in which the foam raw material solution is cast on the skin 15 which is temporarily attached to the surface of the lower mold concave portion 4, and the mold is clamped. In the cavity 10 defined by the lower mold concave portion 4 and the upper mold convex portion 9, the foam raw material solution is foamed and cured, and at the same time, fixed to the insert 13 and the skin 15 to be integrally molded, and then taken out from the mold to be inserted from the insert 13. By removing the sealing material 14, the instrument panel has a front surface covered with a skin and a back surface which is lined with an insert and whose peripheral edge is the rising portion 12.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the mold described in Japanese Patent No. 4914, each time the mold is opened and closed, the elastic seal block rubs against the mating surface and is worn or compressed and deformed, and especially when the mold is repeatedly opened and closed many times, the peripheral edge rises. In the case of manufacturing a molded body having a closed side wall, the sealing action becomes weak and it is necessary to frequently replace the seal block. In the method of sealing the cavity with the sealing material that is fixed to the insert shown in Fig. 4, the sealing is unsatisfactory, and the undiluted foam liquid leaks from the contact surface between the sealing material and the lower mold and adheres to the portion located outside the design of the insert. I have something to do. Since the cured product of the foam material liquid is fixed to the insert with a large adhesive force, when the cured product of the foam material liquid is fixed, many steps are required for finishing such as removal thereof.
In addition, since the insert is easily deformed during handling, the sealing material should be placed at a specified position on the insert, especially when manufacturing a foamed product in which the height of the side wall from the reference bottom surface is partially changed. Since it is difficult to fix the sealing material accurately, the side wall shape accuracy has not reached a sufficiently satisfactory level.

INDUSTRIAL APPLICABILITY The present invention is used for foaming and hardening a foaming stock solution in which at least two kinds of raw material liquids, which are foamed and hardened by being mixed, are foamed and hardened to form a shape in which a peripheral edge rises to form a side wall. (EN) Provided is a foam molding die in which the foam raw material liquid does not enter the mating surface during foam hardening, and a tray-shaped foam molding body having a peripheral edge rising and forming a side wall using the foam molding die and the insert are integrated during foam molding. The present invention has been made for the purpose of providing a method for producing a foamed molded article that has been made into a material.

[0006]

As a result of repeated studies to solve the above problems, the present inventor introduced high pressure gas into a tube formed of a material having a large breaking elongation to expand the tube, and The inventors have found a method for sealing the opening and completed the present invention. That is, the first invention of claim 1 of the present invention is defined by a lower mold having a concave portion on the upper surface and an upper mold having a convex portion that is fitted into the concave portion of the lower mold with a space. A foam mold that has a cavity and is used to mold the foam liquid concentrate cast into the cavity into a foam mold with a concave cross-section that forms a side wall with a rising rim like a tray. An annular groove oriented in the circumferential direction of the recess is provided near the upper end of the wall surface of the side wall of the recess, and an expandable and contractible seal tube made of an elastic material, at least one end of which communicates with a high-pressure gas source, is fitted into the annular groove.
Adjust the flow rate of the gas introduced into the seal tube.
The air tightness of the cavity makes it easy
To the extent that it is discharged, increase as foaming progresses, and finally
Configured so that product gas can be prevented from leaking
It is a foamed mold.

The second aspect of the present invention is the first aspect of the present invention.
The present invention relates to a method for producing an insert-backed foam molded article using the foam molding die of the invention. That is, the second aspect of the present invention is to provide an elastic material in which a concave portion for forming a cavity is provided on the upper surface, and at least one end communicates with a high-pressure gas source in an annular groove provided in the circumferential direction of the concave portion near the upper end of the side wall surface of the concave portion. Using a foaming mold made up of a lower mold in which an expandable and contractible seal tube is fitted, and an upper mold having an upper mold convex part that fits into a lower mold concave part while providing a space in which a cavity is formed. In the method of manufacturing a foamed molded product in which the periphery rises like a tray to form a side wall and the concave surface is lined with an insert, the foamed raw material liquid is cast in the lower mold concave part and the surface of the upper mold convex part After the insert molded in the same shape as the upper mold is temporarily fixed to the convex part of the upper mold, the upper mold is placed on the lower mold in which the undiluted foam is cast and the mold is closed, and then high-pressure gas is injected into the seal tube. Introduce seal chew The by inflating until pressed in contact with the opposite insert, a manufacturing method of the insert integrally foamed molded body foam molding to seal the upper end of the rising portion of the cavity.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Details of a foam molding die according to claim 1 of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a foaming mold. A foam molding die 1 made of metal, synthetic resin or the like can be divided into an upper mold 3 and a lower mold 2, and the lower mold 2 holds the undiluted foam liquid and is foam-molded to obtain a foam. A lower mold recess 4 having a molding surface for casting the outer shape of the body is provided as a recess, and an annular groove 6 that surrounds the lower mold recess 4 is provided near the upper end of the wall surface of the side wall 5 of the lower mold recess 4. At least one end of the seal tube 7, which is connected to the air supply port 8 and is freely expandable and contractible, is fitted in a state where most of the cross section is buried in the annular groove 6. The seal tube 7 is formed of an elastic material such as polyurethane, natural rubber, synthetic rubber, or thermoplastic elastomer having a large breaking elongation, and the cross-sectional shape is not limited, and may be circular, elliptical, or polygonal. On the other hand, the upper die 3 is provided with an upper die projection 9 having a cross section smaller than that of the lower die depression 4 and having a molding surface that fits into the lower die depression 4 to cast the inner surface shape of the foamed molded article. 4 and the upper convex portion 9
The cavity 10 defined by 1 has a rising portion 12 and has a shape in which the foamed raw material liquid is foam-molded into a shape in which the peripheral edge rises like a tray and forms a side wall.

The production of a foam molded article using the foam molding die of the present invention is carried out as follows. After casting a predetermined amount of the undiluted foam solution into the lower mold recess 4 and closing the upper mold 3, a seal tube is introduced from an air supply port 8 communicating with a high-pressure gas source (not shown) such as an air compression pump or a nitrogen cylinder. High-pressure gas is introduced into 7.
The seal tube 7 into which the high-pressure gas has been introduced expands as shown by the chain line to come into contact with the facing surface of the upper mold 3, and the cavity 1
The cavity 10 is sealed at the upper end of the rising portion 12 of 0. By the seal tube 7, the cavity 10 is foamed so that the foaming undiluted liquid having an increased volume is prevented from leaking, and the foaming undiluted liquid does not enter the mating surface of the molding die and leak out of the mold. When the foaming and hardening of the raw foam material is completed in the cavity 10, the air supply port 8 is opened to the atmosphere or is connected to a decompression pump to reduce the pressure in the seal tube 7 and contract the seal tube 7, Then, the foam molding die 1 is opened and the foam molding 11 is taken out. The pressure of the gas introduced into the seal tube 7 is determined in consideration of the thickness and thickness of the seal tube 7, the modulus of the tube material, the cross-sectional shape, the degree of expansion, etc., but the preferred range is 50 to 500.
kPa. In general, when the airtightness of the cavity is high, the air in the cavity cannot escape to the outside and thus remains, and the air may be caught in the foam and form large bubbles. Those with large air bubbles are defective products called air inclusions. On the contrary, when the airtightness is low, the gas generated by the chemical reaction escapes to the outside of the cavity, the gas necessary for foaming is insufficient, and the foamed tissue is disturbed, and a fragile portion called crush may occur. . If a crash occurs, it becomes a defective product. By using the foaming mold of the present invention, the flow rate of the gas introduced into the seal tube 7 is adjusted to gradually increase the internal pressure of the seal tube 7 so that the airtightness of the cavity is easily exhausted in the initial stage of mold clamping. The generation of the defective product can be prevented by increasing the foaming rate as the foaming progresses and finally preventing the generated gas from leaking.

Most of the foamed molded products having a generally concave cross section are used by being attached to a structure composed of a plurality of members. Since it is not strong enough to be directly attached to the structure using bolts, it is lined and attached via the liner. Since the foam stock solution has good adhesiveness, as shown in FIG. 2 or FIG. 4, a backing material is usually added to the inner surface of the foaming mold so that the foam stock solution is cured and foamed. Bonding is done at the same time. It is so-called integral foam molding. Details of integral foam molding using the foam molding die of the present invention will be described with reference to FIG. FIG. 2 is a partial cross-sectional view showing a state where integral foam molding is performed using the foam molding die of the present invention. The foam molding die 1 can be divided into a lower die 2 and an upper die 3, and an annular groove 6 oriented in the wall circumferential direction is provided in the lower die 2 near the upper end of a side wall surface 5 of a lower die recess 4 forming a cavity 10. An expandable / contractible seal tube 7 having at least one end communicating with a high-pressure gas source is fitted in the annular groove 6 such that most of its cross section is sunk at normal pressure and most of it is exposed at high pressure. On the other hand, the upper mold 3 is provided with an upper mold protrusion 9 having a cross section smaller than that of the lower mold recess 4 so that a space is formed between the upper mold 3 and the lower mold recess 4 to form a cavity 10 having a substantially concave cross section. It is projected. Using the foam molding die 1 described above, a foam molded body having a concave surface lined with an insert is manufactured as follows. First, the foam stock solution is cast into the lower mold recess 4, and the insert 13 molded in a shape substantially the same as the surface shape of the upper mold protrusion 9 is previously formed.
The upper mold 3 which has been temporarily fixed to is fixed on the lower mold 2 in which the above-mentioned undiluted solution of the foam has been cast, and the mold is clamped. Subsequently, a high pressure gas is introduced into the seal tube 7 to gradually increase the pressure, and the seal tube 7 whose cross section is indicated by the broken line in FIG. 2 is expanded as shown by the solid line to press the facing surface of the insert 13 to form a cavity. The upper end of the rising part 12 of 10 is sealed.
During this period, the undiluted foam solution fills the cavity 10 and expels the air in the cavity 10 and is molded into the same shape as the cavity 10 while being fixed to the insert 13 arranged on the concave surface. A foamed molding that is cured and lined with the insert 13 is formed. By opening the foam molding die and taking it out, an integral foam molding with the insert can be obtained.

[0011]

[Example] An instrument panel for mounting an instrument of a car was prototyped using the foaming mold of the present invention. The cross-sectional shape of the instrument panel is similar to that of the cavity of the foaming mold shown in FIG. 4, the peripheral edge rises to form a side wall, and the cross-sectional shape is a concave shape. A plurality of recesses 16 for accommodating instruments are provided on the surface which is located on the opposite side and which is the outer surface. As shown in FIG. 3, which is a partial cross-sectional view showing a state in which the skin and the insert are integrally foam-molded by using a foam-molding die, the instrument panel has a glass short fiber on the surface on the concave side. An insert 13 made of mixed acrylonitrile-styrene copolymer resin is fixed and lined, and the surface on the opposite side is covered with a skin 15 formed by a slush method of vinyl chloride resin to form an outer surface. The foaming mold 1 used for the trial manufacture of the above instrument panel is made of thermosetting synthetic resin or the like, and is provided with a concave portion 4 forming a cavity 10 as shown in FIG. Lower mold 2 and an upper mold 3 provided with a convex portion 9 having a cross section smaller than that of the lower mold concave portion 4.
And An annular groove 6 whose cross-sectional shape is a chamfered shape of a partial circle cut at 80% of the diameter is provided on the wall surface of the side wall 5 of the recess of the lower mold 2, and the annular groove 6 has an annular cross section as shown by the broken line. A seal tube 7 made of natural rubber, which has a circular shape with the same diameter as the groove and has one end communicating with the air supply port and the other end closed, is fitted.

The above instrument panel was prototyped using the above foaming mold by the method described below. A skin 15 shaped in the same shape as the surface shape of the lower mold recess 4 of the foaming mold 1 is placed in the lower mold recess 4, and a liquid polyisocyanate compound, a liquid polyamine compound, a foaming agent, etc. are provided on the upper surface side thereof. Approximately ⅕ of the volume of the cavity 10 defined by the upper mold 3 and the lower mold 2 is poured into the undiluted foam solution, and the insert 13 having the same shape as the surface shape of the convex portion 9 of the upper mold is placed on top. Upper mold 3 which is temporarily attached to the mold protrusion 9 in advance
After closing, the seal tube 7 fitted in the annular groove 6 was connected to the air compression pump via a pressure reducing valve whose pressure was adjusted to 100 kPa, and the pressure inside the seal tube 7 was 100 kP.
Introduce high pressure air so that it takes about 30 seconds to reach a. The seal tube 7 expands to change its cross-sectional shape from a circle shown by a chain line to a shape shown by a solid line in about 30 seconds, and by pressing the end of the skin 15 against the insert 13, the rising portion 12 of the cavity 10 is pushed. The upper end of is closed and becomes airtight. While the cross-sectional shape of the seal tube 7 is changing, the undiluted foam solution foams and its volume increases,
The air in the cavity 10 is exhausted. After the undiluted foam solution foams and fills the cavity 9 and hardens, the seal tube 7 is made to communicate with the atmosphere and contracted, and then the foam molding die is opened to form a foam molding body integrated with the insert 13 and the skin 15. I took it out. Since the foamed molded body 11 manufactured by the above method is foamed and molded in the completely sealed cavity, the foamed raw material liquid may leak out of the cavity and adhere to the portion of the insert located outside the cavity. Disappear. Moreover, since the upper end of the rising portion 12 is positioned by the annular groove 6, the height of the rising portion 12 is highly accurate. Since the strength of the cavity seal is adjusted, the occurrence of defective products such as air entering and crashing can be prevented.

[0013]

[Effects of the Invention] In the foam molding of a foam molded body whose peripheral edge rises like a tray to form a side wall, an annular groove is provided near the upper end of the wall surface of the side wall of the recess of the lower mold and a seal tube that is expandable and contractible is fitted therein. After pouring the raw material for the foam into the cavity using the foam molding die, the high pressure gas is introduced into the seal tube and expanded until the seal tube presses the facing surface. The air-tightness prevents the undiluted solution of the foam from leaking out of the cavity, and the accuracy of the height of the rising portion of the foamed molded article is increased. Further, generation of defective products such as air entering and crashing is prevented.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a foaming mold of the present invention.

FIG. 2 is a partial cross-sectional view showing a state in which an insert and integral foam molding are performed using the foam molding die of the present invention.

FIG. 3 is a partial cross-sectional view showing a state where the foam molding die of the present invention is used for integral foam molding with a skin and an insert.

FIG. 4 is a cross-sectional view showing a state in which an instrument panel is integrally foam-molded by using a conventional foam-molding die.

[Explanation of symbols]

1 Foaming mold 2 Lower mold 3 Upper mold 4 Lower mold recess 5 Side wall of recess 6 annular groove 7 Seal tube 8 Air supply port 9 Upper mold protrusion 10 cavities 11 Foam molding 12 Rising part 13 inserts 14 Seal material 15 skins 16 hollow

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B29C 33/00-33/76 B29C 39/26-39/36 B29C 41/38-41/44 B29C 43 / 36-43-42,43 / 50 B29C 45/26-45/44 B29C 45/64-45 / 68,45 / 73 B29C 49/48-49 / 56,49 / 70 B29C 51/31-51/40, 51/44

Claims (2)

(57) [Claims] 1. A foaming mold having a cavity defined by a lower mold having a concave portion on its upper surface and an upper mold having a convex portion that is fitted into the concave portion of the lower mold with a space, and has a peripheral edge. In a mold used for a foamed molded product that has a side wall that rises like a tray and has a concave cross-sectional shape, an annular groove oriented in the circumferential direction of the recess is formed near the top of the wall of the side wall of the recess of the lower mold. An expandable and contractible seal tube made of an elastic material, at least one end of which is connected to the high pressure gas source, is fitted in the annular groove, and the flow rate of the gas introduced into the seal tube is adjusted to adjust the flow rate.
The inner pressure of the tube to gradually increase the airtightness of the cavity.
At the beginning of tightening, make sure that the air is easily exhausted to prevent foaming.
As the process progresses, raise it to prevent the product gas from leaking at the end.
A foaming mold which is configured so that it can be molded. 2. A method of integrally foam-molding an insert material, which serves as a reinforcing material for a foam-molded article, using the foam-molding die according to claim 1, wherein the shape is approximately the same as the surface shape of the upper mold convex portion. Temporarily fix the insert to the convex part of the upper mold, inject the foaming undiluted solution into the concave part of the lower mold, at least close the mold, then introduce high-pressure gas into the seal tube and press the seal tube against the opposite insert. A method for producing a molded body integrally foamed with an insert, characterized in that the upper end of the rising portion of the cavity is sealed and foam-molded by inflating the insert.