JP3459861B2 - Molding method and molding apparatus for foam molded articles - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for molding foam-molded articles, and more particularly to a measure for discharging a gas generated during the foaming of a hard foam resin raw material constituting a base material out of a mold. Is.

[0002]

2. Description of the Related Art For example, there is a door trim, which is an interior part of an automobile, in which a hard foamed resin base material made of hard foamed urethane resin or the like is integrally molded on the back surface of a resinous skin. Such a foam-molded article sets a skin on the lower mold in a mold open state of a molding device, and injects a hard foam resin raw material onto the skin in this state or in a mold clamped state, It is molded by foaming and curing in the cavity to form a base material.

At this time, gas is generated during the process of foaming the hard foam resin material. If the generated gas remains without being discharged to the outside of the mold, it becomes voids or pinholes, and the commercial value is reduced. Therefore, for example, JP-A-6-4775.
As disclosed in Japanese Patent Laid-Open No. 4 (1994), it has been conventionally practiced to provide a suction port around the outer periphery of the cavity to forcibly suck out the gas generated in the cavity out of the mold.

[0004]

However, even if the gas is forcibly excluded in this way, the progress of foam hardening is generally
Since the central part where the hard foam resin raw material is injected first is more advanced than the cavity peripheral part where it is injected later, the gas generated a little earlier in the central part is confined by the raw material on the outside and there is no escape. Sometimes, it wasn't perfect.

By the way, there is one in which a skin is composed of a solid layer having a front surface side and a soft foamed resin layer integrally molded on the back surface of the solid layer. In this case, if the gas escapes and stops between the soft foamed resin layer of the epidermis and the base material as described above, the sense of unity between the two is impaired, and the epidermis and base material are separated from the part where the gas has stopped. There is a problem.

The present invention has been made in view of the above points, and an object thereof is to occur in a cavity when a two-layer structure of a solid layer and a soft foamed resin layer is adopted as a skin. The purpose of this is to quickly and surely release the generated gas and prevent the peeling of the skin and the substrate due to the interposition of the gas.

[0007]

In order to achieve the above object, the present invention is designed so that the gas generated in the cavity is forcibly sucked out of the mold through the soft foamed resin layer of the skin. Characterize.

Specifically, according to the present invention, a hard foam resin base material is integrally formed on the back surface of a resin skin, and the solid skin is integrally formed on the front surface side of the solid layer and the back surface of the solid layer. The following means for solving the problems were taken for a molding method and a molding apparatus of a foam molded article composed of a soft foamed resin layer.

That is, the first and second solving means of the present invention relate to the former molding method. In the first solving means, first, the skin is placed with the soft foamed resin layer facing upward. Set in the lower mold of the molding device in the mold open state. Next, after the upper mold of the molding apparatus is closed and the mold is clamped, or in the mold open state, the hard foam resin raw material is injected onto the soft foam resin layer of the skin. Then, in the mold clamping state of the molding device, the porous sealing material is brought into contact with the vicinity of the end of the soft foamed resin layer of the skin, and the porous sealing material is formed in the cavity in the process of foaming and hardening the hard foamed resin raw material. The hard foamed resin raw material is foamed and expanded by contacting with the porous sealing material to continue vacuuming for a predetermined time.

A second solving means is the first solving means, wherein when the foam molded article is released from the molding apparatus after molding, a porous sealing material is adhered to the back surface of the skin by a hard foam resin raw material, It is characterized in that the sealing material is cut off together with the end portion of the molded product during the subsequent processing of the molded product end.

The third and fourth means for solving the problems of the present invention relate to the latter molding device. In the third means for solving the problems, the outer skin is set with the soft foamed resin layer facing upward. Provide a mold. Further, an upper mold is provided which forms a cavity into which the hard foaming resin raw material is injected between the lower mold and the lower mold. Further, a suction groove portion for vacuuming the cavity in the mold clamped state is provided in the vicinity of the outer periphery of the upper mold facing the lower mold so as to surround the cavity. In addition, a vacuum introducing hole is opened in the upper mold, and the vacuum introducing hole is communicated with the suction concave streak portion. Furthermore, a porous seal material is detachably attached to at least the suction groove around the opening of the vacuum introduction hole, and the porous seal material is attached to the end of the soft foamed resin layer of the skin set in the lower mold. It is characterized in that it is brought into contact with the vicinity in a mold clamped state.

A fourth solving means is the same as the third solving means, in which a sealing means is provided outside the suction groove near the outer periphery of the upper mold or the lower mold so as to surround the cavity, and the sealing material and the mold are clamped. It is characterized in that the skin terminal is sandwiched between the mold surfaces facing each other in this state.

With the above-mentioned structure, in the first to fourth solving means of the present invention, when the suction concave portion is evacuated, this negative pressure action extends to the soft foamed resin layer of the abutting skin and the soft foamed resin layer. Is a communicating bubble, the soft foamed resin layer is evacuated over a wide area. Moreover, since this vacuum evacuation is continued for a predetermined time even after the hard foamed resin raw material foam expands and contacts the porous sealing material, the gas generated in the process of foaming the hard foamed resin raw material in the cavity is It is forcibly sucked into the vicinity of the end of the skin through the soft foamed resin layer of the skin, and quickly and surely discharged out of the mold. For this reason, the soft foamed resin layer of the skin and the base material are firmly bonded together without causing a bonding failure and do not separate.

In particular, according to the second solution, since the porous sealing material comes off from the suction groove portion at the same time as the mold release of the foamed molded product, the labor for removal can be saved and the man-hours can be reduced correspondingly, thereby improving the production efficiency. Increase.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

The present invention relates to a method for molding a foam molded article and a molding apparatus used for the molding method. First, the latter molding apparatus will be described.

FIGS. 1 to 6 show the usage state of the molding apparatus according to each molding process. In this example, the foamed molded product is a door trim D as an automobile interior product (a completed product is shown in FIG. 7). Indicates. 1 to 6, 1 is a fixed lower mold, 3 is a movable upper mold that is attached to the lower mold 1 by a hinge 5 so as to be openable and closable in the vertical direction. A part of the slide core 7 constitutes the slide core 7, and as shown in FIG. 6, the slide core 7 is horizontally retracted in order to prevent the mold from being unmoldable by the undercut portion d6 of the door trim D.

The resin skin d1 is set on the lower mold 1 with its back surface facing upward. The skin d1 is a solid layer d2 made of polyvinyl chloride or the like on the surface side.
And a soft foamed resin layer d3 made of soft foamed urethane resin or the like integrally formed on the back surface of the solid layer d2, which has a two-layer structure and is predetermined by a slush molding method or a vacuum molding method. It is molded into a shape. That is, the skin d1 is set in the lower mold 1 with the back side soft foamed resin layer d3 facing upward. Also,
In the mold clamped state in which the upper mold 3 is rotated downward, between the upper mold 3 and the lower mold 1, a hard foamed resin raw material R made of a hard foamed urethane resin or the like that constitutes the base material d4 of the door trim D. The cavity 9 into which is injected is configured.

In the vicinity of the outer periphery of the upper mold 3 facing the lower mold 1, there is a suction groove 11 that opens downward.
The suction recessed portion 11 communicates with a vacuum introduction hole 12 formed in the upper die 3, and the vacuum introduction hole 12 is connected to a vacuum pump (not shown) through a pipe 13 The suction concave streak portion 11 is made to have a negative pressure by the operation of the vacuum pump, and the cavity 9 is evacuated in a mold clamped state.

A feature of the present invention is that the above vacuum introducing hole 12 is provided.
On the suction concave portion 11 around the opening, the skin d
A porous sealing material 15 made of a soft urethane resin similar to the soft foamed resin layer d3 of No. 1 is detachably mounted,
The porous sealing material 15 is adapted to come into contact with the vicinity of the end of the soft foamed resin layer d3 of the skin d1 set in the lower mold 1 in a mold clamped state. The porous sealing material 15 and the soft foamed resin layer d3 of the skin d1 are composed of open cells due to their properties, and the base material d4 is composed of closed cells due to their properties.

Near the outer periphery of the lower mold 1, the suction groove 1
A groove groove 17 is provided on the outer side of the groove 1 around the entire circumference thereof, and an air tube 19 as a sealing means is fitted in the groove groove 17 so as to surround the cavity 9. Is expanded by supplying pressurized air from a compression pump (not shown), and the outer surface d1 end is sandwiched between the mold surface of the upper mold 3 and the expanded air tube 19 which face each other in the mold clamped state.

The door trim D, which is integrally formed with the base material d4 on the back surface of the skin d1, is molded by the molding apparatus configured as described above. The base material d of the door trim D is molded.
4, a glass mat d5 as a reinforcing material is embedded.

Next, a method of forming the door trim D will be described.

First, as shown in FIG. 2, the upper mold 3 of the molding apparatus is rotated upward with the hinge 5 as the center of rotation to open the mold, and the skin d1 is oriented with the soft foamed resin layer d3 facing upward. The mold is set in the lower mold 1 in the mold open state, and the glass mat d5 is set thereon.

Next, as shown in FIG. 3, the hard foaming resin material R is sprayed and injected by the injection gun 21 onto the soft foaming resin layer d3 of the skin d1 in the mold open state of the molding apparatus. At this time, the slide core 7 is horizontally retracted so that the undercut portion d6 of the skin d1 is shifted downward and directed upward, so that the hard foam resin raw material R is easily sprayed onto the inner surface of the undercut portion d6.

After that, as shown in FIG. 4, the slide core 7 is horizontally advanced and returned to the original position, and then the upper mold 3 is rotated downward around the hinge 5 as a rotation center to close the mold. Then, in the mold clamping state of this molding apparatus, the porous sealing material 15 mounted on the suction concave portion 11 of the upper mold 3 is brought into contact with the vicinity of the end of the soft foamed resin layer d3 of the skin d1. Further, the air tube 19 fitted in the groove 17 of the lower mold 1 is expanded by operating a compression pump, and the expanded air tube 19 and the mold surface of the upper mold 3 clamp the end of the skin d1. And seal. Then, the vacuum pump is operated in the process of the hard foam resin raw material R being foamed and cured, and the suction concave streak portion 11 is set to a negative pressure to evacuate the inside of the cavity 9 through the porous seal material 15. This evacuation is continued for a predetermined time even after the hard foamed resin material R foams and expands and comes into contact with the porous sealing material 15. In addition, the suction concave portion 1
The hard foamed resin raw material R also intrudes into a place where the porous sealing material 15 of No. 1 is not attached.

As a result, due to the negative pressure action, the epidermis d1
The soft foamed resin layer d3 can be evacuated over a wide range, and even if the gas generated by the foaming of the hard foamed resin raw material R remains in the inner part of the cavity 9, it is forcibly sucked and quickly removed from the mold. It can be discharged quickly and reliably. Therefore, the soft foamed resin layer d3 and the base material d4 can be firmly joined together and prevented from peeling without causing joint failure.

After that, as shown in FIG. 5, the hard foam resin raw material R is completely foamed and cured to form a base material d4, and a door trim D in which the base material d4 is integrally formed on the back surface of the skin d1 is obtained. At this time, the porous sealing material 1 of the suction recessed portion 11
The hard foamed resin raw material R that has penetrated into the place where 5 is not attached also foams and hardens to become the foamed hardened resin d'4.

Thereafter, as shown in FIG. 6, the slide core 7 is horizontally retracted and retracted so as not to interfere with the undercut portion d6 of the door trim D, and then the upper mold 3 is rotated about the hinge 5 as a center of rotation. Rotate upward to open the mold.
In this state, the door trim D molded as shown by the phantom line in FIG. 6 adheres to the upper mold 3 and is removed from the lower mold 1. This door trim D is placed on the upper mold 3 by the operator as shown by the solid line in FIG.
It is removed from the mold and released from the molding device.
Since the porous sealing material 15 mounted on the suction groove portion 11 of the upper mold 3 is attached to the back surface of the skin d1 (soft foamed resin layer d3) by the hard foamed resin raw material R that has penetrated during molding, FIG. As shown by the solid line, the mold is removed from the door trim D at the same time to be removed from the suction concave portion 11. As a result, the labor for removing the porous sealing material 15 can be saved, the number of steps can be reduced, and the production efficiency can be improved. Further, the foamed cured resin d'4 of the hard foamed resin raw material R that has infiltrated into the portion of the suction recessed portion 11 where the porous sealant 15 is not mounted and foamed and hardened is also the porous sealant when the door trim D is released from the mold. It is separated from the suction groove 11 together with 15.

The door trim D thus demolded is then carried into a trimming process as a molded product end treatment process, and the porous seal material 15 and the foamed cured resin d'are carried.
4 and the end portion of the door trim D are cut out from the alternate long and short dash line portion (denoted by reference numeral t) in FIG. 6 to obtain a door trim D as a finished product as shown in FIG.

In the above molding method, the hard foam resin raw material R is injected into the cavity 9 in the mold open state. However, an injection hole is formed in the upper mold 3 and the injection molding hole is injected into the cavity 9 from the injection hole. You may do it.

Further, the porous sealing material 15 may be mounted not only around the opening of the vacuum introduction hole 12 of the suction groove 11 but also around the entire circumference of the suction groove 11. If it is mounted only around the opening of the vacuum introducing hole 12 of the suction concave portion 11 as in the above embodiment, the porous sealing material 15
The use amount of is reduced and the cost can be reduced.

Further, it goes without saying that the foam-molded product is not limited to the door trim D, but may be another interior product such as an instrument panel, and is not limited to an automobile interior product.

[0034]

As described above, according to the present invention according to claims 1 to 4, the porous sealing material is brought into contact with the end portion of the soft foamed resin layer of the skin, and the porous sealing material is interposed therebetween. The gas generated in the cavity can be promptly and reliably forcedly sucked out of the mold through the soft foamed resin layer. In addition, this makes it possible to increase the sense of unity between the skin and the base material and prevent the peeling of the both.

According to the second aspect of the present invention, in particular, the porous sealing material is removed from the suction groove portion at the same time as the mold release of the foamed molded product. Therefore, the number of steps is reduced and the production efficiency is reduced. Is to increase

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a molding apparatus showing an enlarged portion of a porous seal material mounting portion in FIG.

FIG. 2 is a cross-sectional view of a molding apparatus showing a state in which a skin and a glass mat are set in a lower mold in a mold open state.

FIG. 3 is a cross-sectional view of a molding apparatus showing a state of injecting a foamed resin raw material.

FIG. 4 is a cross-sectional view of a molding apparatus showing a mold clamping state after injecting a foamed resin raw material.

FIG. 5 is a cross-sectional view of the molding apparatus showing a mold clamping state immediately after molding.

FIG. 6 is a cross-sectional view of the molding apparatus showing a state where the door trim is removed from the mold after opening the mold.

FIG. 7 is a cross-sectional view of a door trim as a finished product with a terminal portion cut off.

[Explanation of symbols]

1 Lower mold 3 Upper mold 9 cavities 11 suction groove 12 Vacuum introduction hole 15 Porous sealing material 19 Air tube (seal means) D door trim (foam molded product) d1 epidermis d2 solid layer d3 Soft foamed resin layer d4 base material R Rigid foam resin raw material

─────────────────────────────────────────────────── --- Continued from the front page (56) References JP-A-4-516 (JP, A) JP-A-6-293031 (JP, A) JP-A 61-125816 (JP, A) JP-A 61- 246056 (JP, A) Actual opening Sho-58-161599 (JP, U) Actual opening 63-74349 (JP, U) Actual opening Flat 7-23515 (JP, U) Special table flat 6-504964 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B29C 39/00-39/44

Claims (4)

(57) [Claims] 1. A solid foamed resin base material is integrally formed on the back surface of a resin skin, and a solid layer whose front surface is the skin and a soft foamed resin layer integrally formed on the back surface of the solid layer. A method of molding a foamed molded article, comprising: setting the outer skin to a lower mold of a molding device in a mold open state with the soft foamed resin layer facing upward, and then closing the upper mold of the molding device. After the mold is clamped or the mold is opened, the hard foamed resin raw material is injected onto the soft foamed resin layer of the skin, and then, in the mold clamped state of the molding device, the porous foam is formed in the vicinity of the end of the soft foamed resin layer of the skin. A sealing material is brought into contact, and the inside of the cavity is evacuated through the porous sealing material in the process of foaming and hardening of the hard foaming resin raw material, and the hard foaming resin raw material foam-expands and comes into contact with the porous sealing material. Continue vacuuming for a predetermined time afterwards A method for molding a foam-molded article, comprising: 2. When the foamed molded product is removed from the molding apparatus after molding, the porous sealing material is adhered to the back surface of the skin by the hard foaming resin raw material, and the porous sealing material is subjected to the subsequent end treatment of the molded product. The method for molding a foamed molded product according to claim 1, wherein the molded product is cut together with the end portion. 3. A hard foam resin base material is integrally formed on the back surface of a resin skin, and a solid layer having the skin as the front surface side and a soft foam resin layer integrally formed on the back surface of the solid layer. A molding apparatus for a foam-molded product configured, comprising: a lower mold in which the skin is set with a soft foamed resin layer facing upward, and a cavity into which a hard foamed resin raw material is injected, in a mold-clamped state. An upper mold formed between the mold and a mold, a suction groove provided near the outer periphery of the upper mold facing the lower mold so as to surround the cavity, and a vacuum for drawing the cavity in a mold clamped state, and the suction groove. And a vacuum introduction hole that is open to the upper mold and communicates with the upper mold, and at least the suction recessed portion around the opening of the vacuum introduction hole is detachably mounted, and the soft foam resin of the outer skin set in the lower mold. Abuts near the end of the layer with the mold clamped Molded foam of the molding apparatus being characterized in that a porous sealing member. 4. A sealing means is provided outside the suction groove near the outer periphery of the upper mold or the lower mold so as to surround the cavity by pressing the skin end with the mold surfaces facing each other in the mold clamped state. The molding apparatus for a foam-molded article according to claim 3, wherein