JP2008260251A - Vacuum molding mold and vacuum molding method using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum molding mold having a simple configuration and controlling scratching and breaking of the skin material in deep-drawing parts. <P>SOLUTION: The vacuum molding mold 10 includes a first mold 11 having a protrusion 11a on the surface of the mold and a second mold 12 having a hollow 12a into which the protrusion 11a is inserted on mold closing and carries out vacuum molding while holding a molding material 14 between the first mold 11 and the second mold 12. An elongation member 11b disposed in the first mold 11 or the second mold 12 elongates the molding material 14 arranged between the first mold 11 and the second mold 12 yet separated from each other before mold closing so as to come into contact with the inside surface of the hollow 12a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vacuum forming technique for vacuum forming a skin material with a thermoplastic foam layer and simultaneously bonding it to a base material, for example, for integrally forming a skin of an automobile interior part, etc., and in particular, forming a deep drawing portion. The present invention relates to a vacuum forming die and a vacuum forming method using the same.

  The vehicle parts such as the instrument panel 1 and the door trim shown in FIG. 7 are formed of a molded part of a thermoplastic resin, and become an insert placed on the mold surface while vacuum forming a skin material lined with a thermoplastic foam layer on the skin. It is produced by bringing it into close contact with the substrate. In particular, the instrument panel 1 is provided with a meter hood portion 2 which is recessed so as to fit a meter panel provided with instruments such as a speedometer. The area of the meter hood portion 2 is formed by so-called deep drawing. The

  In order to perform this type of deep drawing, for example, as shown in FIG. 8, a vacuum mold comprising a cavity mold 3 for molding the front side of the molded product and a core mold 4 for molding the back side of the molded product. Use mold 5. The vacuum mold 5 includes a protrusion 3a on the mold surface of the cavity mold 3, and a recess 4a for receiving the protrusion 3a is formed on the mold surface of the core mold 4 corresponding to the protrusion 3a. ing. When the mold is closed, the protrusion 3a is inserted into the recess 4a and deep drawing is performed.

Here, the production of a molded product using the vacuum mold 5 will be described below.
First, as shown in FIG. 8, a base material 6 serving as an insert is placed on the mold surface of the core mold 4, and a skin material 7 is placed between the cavity mold 3 and the core mold 4 in tandem with this. Deploy. Here, the skin material 7 is a skin material single body 7a lined with a foam layer 7b. This skin material 7 is arranged in a heated and softened state. Note that the skin material 7 is held between the cavity mold 3 and the core mold 4 by a clamping device (not shown).

Then, as shown in FIG. 8, the mold is closed while evacuating the air existing between the skin material 7 and the cavity mold 3 from the vacuum suction hole provided in the cavity mold 3. As a result, as shown in FIG. 9, the skin material 7 is vacuum-formed, and at the same time, closely contacts the base material 6, thereby completing the molded product.
Such a vacuum forming method is also disclosed in Patent Document 1.
JP 2006-240191 A

In the conventional vacuum forming method shown in FIGS. 8 and 9, when the deep drawing portion is formed in the skin material 7 by the protruding portion 3a and the recess portion 4a, the cavity mold 3 is indicated by the arrow X as the mold is closed. When the core mold 4 approaches each other, the skin material 7 interferes with the corners A and B such as the projecting portion 3a and the recess 4a, and when the mold closing proceeds from this state, the skin material 7 that contacts the corners A and B. A part of the periphery of the region extends. Further, since the clearance between the base material 6 that is the insert and the cavity mold 3 is narrow, rubbing occurs on the surface of the skin material 7 when the mold is closed.
Therefore, due to such local stretching and rubbing, as shown in FIG. 9, tear D may occur in the skin material 7 after the mold is closed.

  The present invention was created in view of the above points, and it is a first object of the present invention to provide a vacuum forming die that prevents the skin material from being rubbed or torn with the formation of the deep drawing portion when the die is closed. One object is to provide a vacuum forming method using the second object.

  In order to achieve the first object, the present invention provides a first mold in which a protrusion is formed on the mold surface and a second mold in which a recess is formed into which the protrusion is inserted when the mold is closed. A vacuum forming die for vacuum forming by sandwiching a molding material between the first die and the second die, and the first die and the second die separated from each other before closing the die It is characterized by comprising an extending member that extends a molding material disposed between the molds and makes it contact the inner surface of the recess.

  The vacuum forming mold of the present invention preferably includes a compressed air slide mold or a vacuum suction hole as an extension member, and the compressed air slide part projects from the front projecting part into the recessed part before the mold is closed, or the compressed air is ejected. The molding material is brought into contact with the inner surface of the recess by evacuating the recess from the vacuum suction hole before closing.

  In order to achieve the second object, the present invention provides a first mold in which a protrusion is formed on the mold surface and a second mold in which a recess is formed into which the protrusion is inserted when the mold is closed. And an elongated member that extends the molding material disposed between the first mold and the second mold, and the molding material is sandwiched between the first mold and the second mold, and vacuum forming is performed. A vacuum forming method is characterized in that, before the mold is closed, the forming material is stretched by an extending member and brought into contact with the inner surface of the recess.

  According to the present invention, when the mold is closed, the skin material portion corresponding to the recessed portion region is previously extended by the extending member and is in contact with the inner surface of the recessed portion. When entering, the skin material is not subject to interference such as being strongly pulled from the cavity mold or the core mold. Therefore, it is possible to avoid the occurrence of strong local elongation in the skin material and the occurrence of excessive rubbing between the skin material and the cavity mold. Therefore, according to the present invention, it is possible to reliably form a desired deep drawing shape in vacuum forming.

[First embodiment]
Hereinafter, the present invention will be described in detail based on the embodiments shown in the drawings.
1 to 3 show the configuration of the vacuum forming method according to the first embodiment of the present invention.
A vacuum forming die 10 according to the first embodiment is for performing vacuum forming of, for example, an instrument panel as a molded product, and molds a cavity mold 11 that molds the front side of the molded product and a back side of the molded product. A core mold 12.

The cavity mold 11 includes a projecting portion 11a formed by projecting a part of the mold surface outward. Corresponding to this protrusion 11a, the core mold 12 is provided with a recess 12a in the mold surface for receiving the protrusion 11a when the core mold 12 is combined with the cavity mold 11 when the mold is closed.
The cavity mold 11 is provided with a vacuum suction hole (not shown) that opens on the mold surface. When the mold is closed, an external vacuum pump device (not shown) evacuates air existing between a skin material (described later) as a molding material and the cavity mold 11 through the vacuum suction hole.

The above configuration is the same as the conventional vacuum forming die 5, but in the vacuum forming die 10 used in the vacuum forming method according to the first embodiment, the cavity dies 11 are separated from each other before closing the die. It is characterized by having an extending member that extends a skin material (described later) between the cavity mold 11 and the core mold 12 and makes contact with the inner surface of the recess 12a.
Specifically, the extending member is composed of a compressed air slide mold 11b and is provided in a protruding portion 11a of the cavity mold 11 so as to be able to appear and retract. The compressed air slide mold 11b projects downward from the projecting portion 11a immediately before closing the mold, and ejects compressed air from an ejection port (not shown) provided in the periphery as indicated by an arrow. In addition, although illustration is abbreviate | omitted, the compressed air slide type | mold 11b is connected via the hose and the external device which supplies compressed air.

The case where the molded product is vacuum-formed using the vacuum forming die 10 according to the first embodiment will be described below. First, as shown in FIG. A material 13 is placed, and a skin material 14 is disposed between the cavity mold 11 and the core mold 12 in tandem with this. Here, the skin material 14 is a skin material single material 14a lined with a foam layer 14b, and is softened by heating. The skin material 14 is held between the cavity mold 11 and the core mold 12 by being held by a clamping device (not shown). The base material 13 has an opening 13a in a region corresponding to the bottom 12c of the recess 12a.

  Next, the cavity mold 11 is lowered, and when reaching a position where a certain amount of clearance is secured with the core mold 12, the lowering is stopped, and the compressed air slide mold 11b is projected downward from the lower end of the protruding portion 11a. When the compressed air slide mold 11b enters the recess 12a of the core mold 12, the descending is stopped, and compressed air is jetted out from the compressed air slide mold 11b. By this compressed air, the skin material 14 located in the region of the recess 12 a of the core mold 12 is extended and pressed against the mold surface of the core mold 12. Thus, the skin material portion corresponding to the recessed portion region abuts on the inner surface of the recessed portion 12a.

  Thereafter, the ejection of the compressed air from the compressed air slide mold 11b is stopped, and the compressed air slide mold 11b is buried in the protruding portion 11a, and then the cavity mold 11 is lowered toward the core mold 12 to perform the mold closing. In this mold closing, the skin material 14 is vacuum-formed by vacuum evacuation from the vacuum suction hole of the cavity mold 11 and simultaneously brought into close contact with the base material 13 to complete a molded product.

  As described above, in the vacuum forming method according to the first embodiment, when the mold is closed, the skin material portion corresponding to the recessed portion region is previously extended by the pressure slide mold 11b and is in contact with the inner surface of the recessed portion 12a. Therefore, when the protrusion 11a of the cavity mold 11 enters the recess 12a of the core mold 12, the skin material 14 is strongly pulled from the corners A and B (see FIG. 1) of the cavity mold 11 or the core mold 12. Not subject to interference. Therefore, it is possible to avoid occurrence of strong local elongation in the skin material 14 and excessive rubbing between the skin material 14 and the cavity mold 11. Therefore, according to the present embodiment, it is possible to reliably form a desired deep drawing shape in vacuum forming.

[Second Embodiment]
4 to 6 show the configuration of a vacuum forming die according to the second embodiment of the present invention.
The vacuum forming die 20 according to the second embodiment has substantially the same configuration as that of the vacuum forming die 10 shown in FIG. The configuration differs from the vacuum forming die 10 of FIG. 1 in that the vacuum suction hole 12b is provided. Accordingly, the same or similar components as those of the vacuum forming die 10 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The partial male pulling vacuum suction hole 12b is a hole formed in the inner surface of the hollow portion 12a in order to perform a partial male pulling vacuum in the hollow portion 12a immediately before closing the mold. It is connected via a hose or the like. In the illustrated example, the partial male pulling vacuum suction hole 12b is disposed at the bottom 12c of the recess 12a, but may be disposed at the side walls 12d and 12e of the recess 12a.

The case where the molded product is vacuum formed using the vacuum forming die 20 according to the second embodiment will be described below.
First, as shown in FIG. 4, a base material 13 serving as an insert is placed on the mold surface of the core mold 12, and a skin material 14 is disposed between the cavity mold 12 and the core mold 13 in tandem with this. To do. Next, as shown in FIG. 5, the cavity mold 11 is brought close to the core mold 12, and partial vacuum evacuation is performed from the partial male drawing vacuum suction hole 12 b in the recess 12 a of the core mold 12. By this evacuation, the corresponding portion of the skin material 14 located in the region of the recess 12 a of the core mold 12 is sucked against the mold surface of the core mold 12. At this time, the skin material portion corresponding to the recessed portion region extends and contacts the inner surface of the recessed portion 12a.

  Thereafter, the vacuum exhaust from the partial male vacuum suction hole 12b is stopped, and then the cavity mold 11 is lowered to the core mold 12 to perform the mold closing. In this mold closing, the skin material 14 is vacuum-formed by vacuum evacuation from the vacuum suction hole of the cavity mold 11 and simultaneously brought into close contact with the base material 13 to complete a molded product.

  As described above, also in the second vacuum forming method, when the mold is closed, the skin material 14 extends and contacts the shape of the recess 12a of the core mold 12 in advance. When the part 11a enters the hollow part 12a of the core mold 12, there is no interference such as the skin material 14 being strongly pulled by the corner parts A and B of the cavity mold 11 or the core mold 12. Therefore, as in the first embodiment, in the vacuum forming method of the second embodiment, local strong elongation occurs in the skin material 14 or excessive rubbing between the skin material 14 and the cavity mold 11 occurs. Is avoided, and a desired deep-drawn shape can be reliably formed in vacuum forming.

  The present invention can be implemented in various forms without departing from the spirit of the present invention. In the above-described embodiment, the base material 13 is placed on the core mold 12 and the skin material 14 is molded. At the same time, the base material 13 is closely attached. It is also possible to perform vacuum forming by forming a deep-drawn portion in the molding material by disposing only between the cavity mold 11 and the core mold 12 and closing the mold.

  It is apparent that the present invention can be applied not only when the above-described instrument panel is molded but also when a molded product using another skin material is molded.

  Moreover, the vacuum suction hole provided in the cavity mold | type 11 and the vacuum suction hole 12b provided in the hollow part 12a of the core mold | type 12 form a type | mold with a porous raw material, for example, or equip an infinite number of micro holes in a type | mold. The film can be formed by any method.

It is a schematic sectional drawing of the state before mold closing in the structure of the vacuum forming die for enforcing the vacuum forming method concerning a first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing a state in which a skin material is made to follow the shape of a hollow portion of a core mold when molding is performed using the vacuum mold of FIG. 1. It is a schematic sectional drawing which shows the state after mold closing by the vacuum forming die of FIG. It is a schematic sectional drawing which shows the state before mold closing in the other structure of the vacuum forming die for enforcing the vacuum forming method which concerns on 2nd embodiment of this invention. FIG. 5 is a schematic cross-sectional view showing a state in which the skin material is made to follow the shape of the recess of the core mold in the case of molding using the vacuum mold of FIG. 4. It is a schematic sectional drawing which shows the state after mold closing by the vacuum forming die of FIG. It is a perspective view of the instrument panel as a molded article. It is a schematic sectional drawing which shows the state in the middle of mold closing using the conventional vacuum forming type | mold at the time of shaping | molding a deep drawing part into a skin material and vacuum-forming. It is a schematic sectional drawing which shows the state after mold-closing completely from the state of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vacuum forming die 11 Cavity type | mold 11a Protrusion part 11b Pressure-air slide type | mold 12 Core type | mold 12a Depression part 12b Partial male drawing vacuum suction hole 13 Base material 14 Skin material (molding material)
20 Vacuum forming mold

Claims (6)

A first mold having a protrusion on the mold surface and a second mold having a recess into which the protrusion is inserted when the mold is closed. A vacuum forming mold that performs vacuum forming by sandwiching between a mold and the second mold,
It is characterized by comprising an elongating member that extends the molding material arranged between the first mold and the second mold that are separated from each other before closing the mold and makes contact with the inner surface of the recess. Vacuum forming mold. The elongate member is a pneumatic slide type,
The compressed air slide mold is provided so as to be capable of appearing and retracting in the projecting portion of the first mold,
The said pneumatic slide type | mold protrudes in the said hollow part from the said protrusion part before mold closing, The said compressed air is ejected, The said molding material is contact | abutted to the said hollow part inner surface, The Claim 1 characterized by the above-mentioned. Vacuum forming mold. The elongated member comprises a vacuum suction hole;
The vacuum suction hole is provided in the recess of the second mold,
2. The vacuum forming die according to claim 1, wherein the molding material is brought into contact with the inner surface of the hollow portion by evacuating the hollow portion from the vacuum suction hole before closing the die. A first mold in which a protrusion is formed on the mold surface; a second mold in which a recess is formed into which the protrusion is inserted when the mold is closed; and the first mold and the second mold A vacuum forming method in which vacuum forming is performed by sandwiching the molding material between the first mold and the second mold using an extending member that stretches the molding material disposed between the first mold and the second mold,
Before the mold is closed, the molding material is stretched by the elongating member and brought into contact with the inner surface of the hollow portion. The elongate member is a pneumatic slide type,
The compressed air slide mold is provided so as to be capable of appearing and retracting in the projecting portion of the first mold,
5. The molding material is brought into contact with the inner surface of the recess portion by causing the compressed air slide portion to protrude from the protrusion portion into the recess portion before the mold is closed, and to eject the compressed air. The vacuum forming method as described. The elongated member comprises a vacuum suction hole;
The vacuum suction hole is provided in the recess of the second mold,
5. The vacuum forming method according to claim 4, wherein the molding material is brought into contact with the inner surface of the dent part by evacuating the inside of the dent part from the vacuum suction hole before closing the mold.

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