JP2001079872A - Foaming mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a mold structure or a molding process from becoming complicated in a foaming mold of a type supplying steam to a cavity filled with foamable beads and subsequently evacuating the cavity. SOLUTION: A chamber 23, which is arranged so as to leave a first molding surface member 22 between a cavity and the chamber 23, is provided in a first mold 20 and a heating fluid supply hole 22a for supplying a heating fluid to the cavity and a heating fluid discharge hole 22b for discharging the heating fluid to the chamber from the cavity are provided at the molding surface member 22 and the heating fluid supply pipe 18 extending from the heating fluid supply hole 22a to the outside of the first mold 20 through the chamber 23 is provided. Further, a vacuum suction device 17 for evacuating the chamber 23 is connected to the first mold 20 through a suction passage 17a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foaming mold and, more particularly, to a mold for foaming molded articles made from foamed beads.

[0002]

2. Description of the Related Art Conventionally, foamed molded articles using foamed beads are generally prepared by filling a cavity of a foaming mold with a large number of foamed beads and then blowing a heating fluid such as steam into the cavity. They are formed by welding each other (see, for example, JP-A-8-34027).

[0003] The foaming mold described in the above-mentioned publication has a cavity formed by a large number of small holes formed in a wall surface (molding surface member) of a chamber provided around a cavity and a small hole of a tube inserted into the cavity. A structure is adopted in which steam is blown into the interior to fuse the foam beads. In this configuration, the tubes are used to spread steam through the cavity. Further, after the foam beads are welded, the vacuum is sucked from a part of the chamber, while cooling water is supplied into the cavity from the other part of the chamber and the pipe to cool the molded product.

[0004]

However, in the above-described conventional structure, a large number of small holes provided in the wall surface of the chamber and the pipe are formed.
It is used as a steam supply hole when supplying steam into the cavity, and is used as a steam discharge hole when suctioning under vacuum. That is, since the steam supply hole and the steam discharge hole are also used, a mechanism for switching between the supply and the discharge of the steam is required, and there has been a problem that the structure and control are likely to be complicated.

Further, since a tube is used, the tube is inserted into the cavity after filling the mold and before filling with the expanded beads, and the tube is pulled out of the cavity when the product is taken out after molding, and the mold is separated. Because of the necessity, a tube driving mechanism is required, and there is a problem that the molding process is complicated.

The present invention has been made in view of the above problems, and has as its object to supply a foam into a cavity filled with foam beads, and then vacuum-suction the mold. Is to prevent the mold structure and the molding process from becoming complicated.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a supply hole and a discharge hole for a heating fluid such as steam are separately provided on a wall surface of a cavity, so that switching between supply and discharge is not required, and steam in the cavity is eliminated. In this way, the mold structure and the molding process are simplified by increasing the fluidity of the mold.

Specifically, a solution taken by the present invention is to fill a cavity formed by a first mold and a second mold with a large number of foam beads and supply a heating fluid into the cavity. It is premised on a foam molding die for molding a foam molded article by welding foam beads to each other.
A first molding die including a chamber disposed between the cavity and the first molding surface member with a heating fluid supply hole for supplying a heating fluid to the cavity; A heating fluid discharge hole for discharging the fluid from the cavity to the chamber; and a heating fluid supply pipe extending from the heating fluid supply hole to the outside of the first molding die through the inside of the chamber. Further, a suction passage for vacuum suction in the chamber is connected to the chamber.

In the above construction, a cooling fluid supply device for supplying a cooling fluid into the chamber and a drain passage for discharging the cooling fluid to the outside of the chamber are provided, and the drain passage and the suction passage are connected via a switching valve. Connection.

According to the above-mentioned means, when performing foam molding, a cavity is first defined by a first mold and a second mold, and a large number of foam beads are filled in the cavity. Next, a heating fluid such as steam is supplied into the cavity from a heating fluid supply hole formed in the first molding surface member between the cavity and the chamber. By connecting the heating fluid supply pipe to an external heating fluid supply device, the heating fluid is blown out from the heating fluid supply device into the cavity through the heating fluid supply pipe inserted through the chamber, and is heated from the heating fluid discharge hole. Discharged into the chamber.

When the heating fluid is supplied into the cavity as described above, the foam beads are welded to each other. After that, by suctioning the inside of the chamber through the suction passage, the heating fluid in the cavity is sucked out of the mold through the heating fluid discharge hole through the chamber and the suction passage.

When a cooling fluid supply device is provided, the heating fluid is supplied into the cavity, then the cooling fluid is supplied into the chamber, and the cooling fluid is discharged from the drain passage. Then, the inside of the chamber is evacuated, and the heating fluid remaining in the cavity is discharged. Since the drain passage and the suction passage are connected via a switching valve, the switching valve is switched to the drain side when the cooling fluid is discharged from the chamber, while the switching valve is suctioned when the chamber is evacuated. Side, and suctions the inside of the chamber from the suction passage through a part of the drain passage.

[0013]

As described above, according to the above solution, while the heating fluid is supplied into the cavity from the heating fluid supply hole, the heating fluid is discharged out of the cavity from the heating fluid discharge hole different from the heating fluid supply hole. The fluidity of the heating fluid in the cavity can be improved without inserting a tube into the cavity. Since the tube is not required in the cavity, the mold structure and the molding step can be simplified.
In addition, since the heating fluid supply hole and the heating fluid discharge hole are separately provided, a mechanism for switching between supply and discharge of the heating fluid is not required, and control is facilitated.

Further, since the heating fluid in the cavity can be suctioned and discharged under vacuum, the temperature of the foamed beads can be rapidly lowered, and the cooling time can be shortened. In particular, when supplying a cooling fluid into the chamber after heating the foam beads, the molded article is cooled to some extent with the cooling fluid, and then the temperature is quickly reduced by vacuum suction, thereby greatly reducing the cooling time. it can.

If the drain passage and the suction passage are connected via a switching valve, the drain passage can be used for vacuum suction of the chamber, and the piping can be simplified.
Cost can be reduced.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 and 2 are structural views showing a foam molding apparatus 10 of the present embodiment. FIG. 3 is a cross-sectional view showing a schematic structure of a foam molded article 1 molded by the foam molding apparatus 10.
FIG. 2 is a partially enlarged cross-sectional view showing a state where the foam molded article 1 is being molded.

-Structure of foam molded article- First, FIGS. 3 and 4
The foam molded article 1 will be described with reference to FIG. The foam molded article 1 is a member constituting an instrument panel of an automobile, and a base material 2 and a skin material 3 are integrally laminated via a foam layer 4. The phantom lines in FIG. 3 indicate components (such as the air conditioning duct 5) attached below the foam molded article 1 in the vehicle.

As shown in FIG. 4, the skin material 3 is made of TPO.
It has a two-layer structure including an outer skin layer 6 formed by slush molding using a powder material of (thermoplastic olefin), and a foam layer 7 formed on the back surface of the outer skin layer by slush molding also using TPO. Then, the skin material 3 is joined to the base material 2 formed of an olefin resin material such as polypropylene via a foam layer 4.

The foam layer 4 is composed of a large number of foam beads 4a made of an olefin resin such as polypropylene or polyethylene. In the expanded beads 4 a, the particles are welded to each other, and are also welded to the base material 2 and the skin material 3. The foam beads 4a are foamed in a raw material stage, but have a property of being welded by further heating.

The base material 2 has a foamed bead inlet 2 a (FIG. 1) for filling foam beads between the base material 2 and the skin material 3, and a filling material between the base material 2 and the skin material 3. A large number of expanded beads 4a, such as high-temperature steam or hot air,
A steam supply port 2b for supplying a heating fluid and a steam discharge port 2c for discharging a heating fluid such as steam from between the base material 2 and the skin material 3 are formed so as to penetrate therethrough. The foam bead inlet 2a has a larger diameter than the foam beads 4a, but the steam supply port 2b and the steam outlet 2c each have a smaller diameter than the foam beads 4a.

-Structure of Foam Molding Apparatus- Next, the foam molding apparatus 10 will be described with reference to FIGS. 1
Reference numeral 1 denotes a foaming mold, which can be set from the first mold 20 on the movable side and the second mold 30 on the fixed side to the mold open state shown in FIG. 1 and the mold closed state shown in FIG. Have been. Reference numeral 12 denotes a second molding die 30 for covering the skin material 3 of the foam molded product 1 with the second molding die 30.
It is a robot to be set on. The robot 12 vacuum-adsorbs the skin material 3 to the molding surface 32a of the second molding die 30 in the state of FIG. 1 in which the first molding die 20 and the second molding die 30 are separated from each other. It is configured to retreat from between.

The first molding die 20 includes an outer frame 21 and a first molding surface member 22, and a first chamber 23 is formed therebetween. The second molding die 30 includes an outer frame 31 and a second molding surface member 32, and a second chamber 33 is formed therebetween.

The first mold 20 includes a bead filling device 13 (see FIG. 2) for supplying foam beads 4a into a cavity formed between the first mold 20 and the second mold 30. A steam supply device (heating fluid supply device) 14 for supplying a heating fluid such as steam to the foam beads 4a in the cavity, and a cooling water supply device (cooling fluid supply device) 15 for cooling the foam molded article 1 And a drain port 16 for discharging drain water from the chamber 23. The first and second molding dies 20 and 30 have a vacuum suction device 1 for vacuum suctioning both chambers 23 and 33.
7 is connected.

The bead filling device 13 includes a raw material silo 41 in which granular foam beads 4a are stored, a pressurizing device 42 for pressurizing and compressing the foam beads 4a, and a filling gun 43 for supplying the foam beads 4a to the cavity. And between the raw material silo 41 and the pressurizing device 42 and between the pressurizing device 42 and the filling gun 43 via supply pipes 44a and 44b, respectively.

The filling gun 43 includes a predetermined amount of foam beads 4a.
A storage cylinder 45 fixed in the first molding die 20 so as to temporarily store it before filling the cavity, and a filling air cylinder 46 fixed to the rear end of the storage cylinder 45 are provided. . A supply port 4 for receiving the expanded beads 4 a from the pressurizing device 42 is provided on the rear end side of the storage cylinder 45.
The supply port 47 is provided with the supply pipe 44 described above.
b is connected. The supply port 47 is provided with an opening / closing valve (not shown), and the opening / closing of the supply port 47 can be controlled by the opening / closing valve.

The distal end of the storage cylinder 45 has a tapered inner surface and a smaller diameter toward the distal end.
The base 2 is fixed to the first molding surface member 22 so as to communicate with the foamed bead inlet 2a. An extruding block 48 that fits into the small-diameter portion at the tip of the storage cylinder 45 is fixed to the tip of the rod of the filling air cylinder 46. The filling air cylinder 46 is configured to be movable between a position where the tip end surface of the extrusion block 48 substantially coincides with the cavity-side surface of the first molding surface member 22 and a position retracted from the supply port 47. I have.

The steam supply device 14 is connected to a steam supply pipe (heating fluid supply pipe) 18 fixed to the first mold 20 and is configured to supply steam to the foam beads 4a in the cavity. The steam supply pipe 18 includes a header 18
a and a branch pipe 18b, and the header 18a
The steam supply device 14 is connected via a steam pipe 18c provided with an on-off valve 18d.

As shown in FIG. 4, the first molding surface member 22 has a steam supply hole (heating fluid supply hole) 22a for supplying steam between the base material 2 and the skin material 3, A steam discharge hole (heating fluid discharge hole) 22 b for discharging steam to the chamber 23 from between the cover material 2 and the skin material 3 is formed.
The branch pipe 18b of the above-described steam supply pipe 18 is connected to the steam supply hole 22a of the first molding surface member 22 and the steam supply port 2b of the base material 2.
It is located at a position that matches. Further, the steam discharge hole 22b of the first molding surface member 22 is
It is arranged at a position corresponding to c.

The cooling water supply device 15 is connected to a cooling water spray pipe 19 fixed in the chamber 23. The cooling water spray pipe 19 has a header 19 made of a pipe material.
a, and nozzles 19b provided at a plurality of positions of the header 19a toward the first molding surface member 22 side. Then, the cooling water supply device 15 and the header 1
9a is connected to a water pipe 19c to supply cooling water to the first pipe.
It can be sprayed toward the molding surface member 22. The water pipe 15c is provided with an on-off valve 19d,
It is possible to switch between spraying and stopping the cooling water.

On the other hand, the second molding die 30 has a number of small holes for vacuum suction (not shown) for setting the skin material 3 formed in advance by slash molding on the molding surface 32a of the second molding surface member 32. Are formed. In addition, the outer frame 31
A suction port 34 is provided on the upper and lower side surfaces of the suction port 34, and the vacuum suction device 17 is connected to the suction port 34 via a vacuum pipe (suction passage) 17a.

The vacuum suction device 17 is also connected to a drain pipe (drain passage) 16a drawn from the drain port 16 of the first molding die 20. A switching valve 17b is provided at a connection point between the drain pipe 16a and the vacuum pipe 17a. The vacuum pipe 17a has a hose 17c for allowing the suction passage 17a to open and close the molds 20 and 30.
Is used. Also, a drain pan 16b is shown at the tip of the drain pipe 16a.

Next, a method for producing the foam molded article 1 will be described.

In this embodiment, first, the base material 2 and the skin material 3
And are molded separately. Although a specific molding method for each of the base material 2 and the skin material 3 is not shown,
Is molded from an olefin resin material such as polypropylene as described above by a molding method such as injection molding,
The skin material 3 is previously formed into two layers of a skin layer 6 and a foam layer 7 by slush molding using a thermoplastic plastic olefin powder material.

As described above, the bead injection port 2a of the substrate 2 is connected to the filling gun 43 provided in the first molding die 20.
Are formed at substantially the same position as the inner hole of the bead storage cylinder 45. Also, the steam supply port 2b and the steam discharge port 2c of the base material 2
Are formed at the same positions as the steam supply holes 22a and the steam discharge holes 22b of the first molding surface member 22.

Next, as shown in FIG. 1, the first molding die 20 and the second molding die 30 are opened, and the skin material 3 (only one layer is formed in FIG. Is set, and the base material 2 is further placed in the first molding die 20.
Is set. At this time, the robot 12 is used for positioning the skin material 3 on the second molding die 30, and the same robot (not shown) is used for positioning the base material 2 on the first molding die 20. And the skin material 3 is the robot 12
After being placed on the second molding die 30 by vacuum suction by the vacuum suction device 17, it is held in close contact with the second molding surface member 32. On the other hand, since the base material 2 is harder than the skin material 3, the rigidity of the base material 2 itself causes the first molding surface member 22.
Can be held in close contact with the first molding surface member 22 as necessary, or other fixing means may be used. The skin material 3 may be fixed using other fixing means instead of vacuum suction.

When the setting of the base material 2 and the skin material 3 is completed,
Next, the first mold 20 which is a movable mold is replaced with the second mold 20 which is a fixed mold.
The mold is moved in the direction of the mold 30, and the mold is clamped as shown in FIG. As a result, a cavity is defined between the base material 2 and the skin material 3. At this time, the rod of the filling air cylinder 46 of the bead filling device 13 is retracted, and the open / close valve of the supply port 47 is open.

Then, after a predetermined amount of the expanded beads 4a pressurized by the pressurizing device 42 is supplied from the supply pipe 44b into the storage cylinder 45 through the supply port 47, the opening and closing valve of the supply port 47 is closed, and the filling port is filled. The rod of the air cylinder 46 is advanced and pushed into the cavity. The expanded beads 4a are compressed and reduced by the pressing device 42, but each particle is compressed, but return to the atmospheric pressure in the cavity, so that the expanded beads 4a are expanded somewhat more than in the pressurized state.
And the skin material 3 are pressed against the first molding surface member 22 and the second molding surface member 32.

Next, from the steam supply device 14 to the steam supply pipe 1
Steam, which is a heating fluid, is supplied continuously or intermittently into the cavity through 8. Then, the vapor diffuses in the cavity and heats the foam beads 4a. The expanded beads 4a are formed by pre-expanding the respective particles. However, upon heating, the respective particles thermally expand, and are heat-welded while being in close contact with each other, and also heat-welded to the base material 2 and the skin material 3. . Thereafter, the steam is discharged into the chamber 23 of the first mold 20 from the steam outlet 2c and the steam outlet 22b. As described above, since the inlet and the outlet of the steam are separate, in the present embodiment, the flowability of the steam in the cavity is good, and the foam beads 4a are uniformly and stably heated in the cavity.

When the heating step is completed, the cooling water spray pipe 19
Cooling water is sprayed from the nozzle 19b toward the first molding surface member 22 to cool the foamed layer 4. At this time, the switching valve 17b is switched to the drain side so that the cooling water is discharged from the drain port 16 through the drain passage 16a to the drain pan 16b. The on-off valve 18d of the steam pipe 18c is closed.

On the other hand, when the spraying of the cooling water is completed, the opening / closing valve 19d of the water pipe 19c is closed and the switching valve 17b is closed.
Is switched to the suction side, and the vacuum suction device 17 is operated. Thereby, the cooling water remaining in the chamber 23 and the steam in the cavity are quickly discharged.

When all the above steps are completed, the second step
By opening the mold 30 and the first mold 20 and taking out the foam molded product 1, the production of the foam molded product is completed.

-Effects of Embodiment- According to this embodiment,
Since the supply hole 22a and the discharge hole 22b of the steam to the cavity are separated to increase the fluidity of the steam in the cavity, it is necessary to have a complicated structure such as inserting a tube into the cavity. In addition, the configuration can be simplified and the molding process can be prevented from becoming complicated. In addition, since the steam supply hole 22a and the discharge hole 22b to the cavity are separated from each other, it is not necessary to switch between supply and discharge of steam when using a shared pipe unlike the related art. This is advantageous in that the control becomes unnecessary and the control becomes easy.

Further, since the cooling water is sprayed into the first chamber 23 and the chamber 23 and the cavity are vacuum-suctioned, the foam molded article 1 is cooled to some extent with the cooling water, and then the vacuum is applied to quickly and quickly. Can be cooled sufficiently. That is, since the temperature can be quickly reduced by vacuum suction without cooling for a long time with cooling water, the total cooling time can be reduced.

The drain passage 16a and the suction passage 17a
Are connected via the switching valve 17b, the drain passage 16a can be used for vacuum suction of the chamber 23, and cost can be reduced by simplifying piping.

In this embodiment, since all the constituent parts of the foam molded article 1 (the base material 2, the skin material 3 and the foam layer 4) are made of an olefin-based resin, compared with the case where other raw materials are used. Another advantage is that the molded product can be easily recycled.

[0047]

Other Embodiments of the Invention The present invention may be configured as follows with respect to the above embodiment.

For example, in the above embodiment, the foam molded article 1
Has a structure in which the base material 2 and the skin material 3 are laminated via the foamed layer 4 made of the foamed beads 4a. However, it is a matter of course that a molded article formed only by the foamed beads 4a may be used.

In the above embodiment, the first molding die 20
Although the supply and discharge of steam are performed from the cavity 23 side, this structure is merely an example, and can be changed as appropriate according to the configuration of the molded product and the mold structure.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a state in which a foaming mold according to an embodiment of the present invention is separated.

FIG. 2 is a sectional view showing a state in which the foaming mold of FIG. 1 is closed.

FIG. 3 is a sectional view showing a schematic structure of a foam molded article.

FIG. 4 is a partially enlarged cross-sectional view showing a state in which a foam molded article is being formed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Foam molded article 2 Base material 2a Foam bead inlet 2b Steam supply port 2c Steam outlet 3 Skin material 4 Foam layer 4a Foam bead 10 Foam molding device 11 Foam mold 13 Bead filling device 14 Steam supply device (Heating fluid supply device) 15) cooling water supply device (cooling fluid supply device) 16a drain pipe (drain passage) 17 vacuum suction device 17a vacuum pipe (suction passage) 17b switching valve 18 steam supply pipe (heating fluid supply pipe) 19 cooling water spray pipe 20th 1 molding die 22 first molding surface member 22a steam supply hole (heating fluid supply hole) 22b vapor discharge hole (heating fluid discharge hole) 23 first chamber (chamber) 30 second molding die 32 second molding surface member 33 second Chamber

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F202 AA03 AD05 AD08 AD17 AD20 AG03 AG20 AH25 CA24 CB01 CB13 CB22 CN14 CN22 4F212 AA03 AD05 AD08 AD17 AD20 AG03 AG20 AH25 UA01 UB01 UB13 UF30 UL06 UN17

Claims (2)

[Claims] 1. A foam formed by filling a large number of foam beads into a cavity formed by a first mold and a second mold, and supplying a heating fluid into the cavity to weld the foam beads to each other. A foam molding die for molding an article, wherein the first molding die includes a chamber arranged with a first molding surface member separated from the cavity, and a heating fluid is provided in the cavity in the molding surface member. A heating fluid supply hole for supplying heating fluid from the cavity to the chamber, and a heating fluid supply pipe extending from the heating fluid supply hole to the outside of the first molding die through the inside of the chamber. A foaming mold in which a suction passage for vacuum suctioning the inside of the chamber is connected to the chamber; 2. A cooling fluid supply device for supplying a cooling fluid into the chamber, and a drain passage for discharging the cooling fluid to the outside of the chamber, wherein the drain passage and the suction passage are connected via a switching valve. The foaming mold according to claim 1.