JP2009190357A - Panel with outer skin made of foam resin, and its molding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a panel with an outer skin made of foam resin, sound and improved in appearance. <P>SOLUTION: The outer skin 5 made of foam resin is integrally injection-molded on the surface of a base material 3. The expansion ratio of the outer skin 5 in a junction area E of the foam resin injected into a cavity 109' and flowing in different directions and joining when molding the outer skin is set lower than the expansion ratio of the other area. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an improvement in a panel with a foamed resin skin and a molding method thereof, and more particularly, to a measure for improving the appearance of the skin corresponding to a joining region of foamed resin injected into a cavity.

Patent Document 1 discloses a method for forming a panel with a foamed resin skin, in which a skin made of foamed resin is integrally injection-molded on the surface of a resin base material. In the molding method, first, in a state where the core mold and the mold are closed, a thermoplastic resin is injected and filled into the cavity to mold the base material. Next, with the base material left in the core mold, the mold mold is replaced with another mold mold, and a foamed resin is injected and filled into the space formed therebetween. Thereafter, when the foamed resin was cooled to some extent, the core mold was retracted to expand the cavity volume and foam the foamed resin, whereby the foamed resin skin was integrally molded on the surface of the substrate. A panel with a foamed resin skin is obtained.
Japanese Patent Laid-Open No. 5-278771 (paragraph 0011 column, paragraph 0012 column, FIG. 1)

  By the way, when a base material having an opening or a protrusion on the surface is disposed in the cavity and the resin is injected from the gate, the resin hits the protrusion and the like and splits into both sides and then merges. In this case, when the panel is molded by the molding method disclosed in Patent Document 1, the foamed resin collides with the joining portion to form a joint portion of the foamed resin, the foamed gas bubbles break from the joint portion, and the gas easily escapes therefrom. Become. For this reason, if the cavity volume is enlarged after the foam resin is injected and filled into the cavity, the foam gas escapes from the joints, and the foam resin is insufficiently foamed at the junction, and the foam resin is sufficient for the molding surface of the mold. However, the surface of the formed skin becomes an avatar-like rough surface, and the commercial value is lowered.

  This invention is made | formed in view of this point, The place made into the objective is providing the panel with the sound foamed resin-made skin which improved the external appearance appearance.

  In order to achieve the above object, the present invention is characterized in that the expansion ratio of the foamed resin injected into the cavity is partially changed.

  Specifically, this invention is directed to a panel with a foamed resin skin, in which a skin made of foamed resin is integrally molded on the surface of a base material, and a molding method thereof, and the following solution is taken.

  That is, the invention according to claims 1 and 2 relates to the former panel with foamed resin skin, and the invention according to claim 1 is different in that the skin is injected into the cavity at the time of skin molding. The foaming ratio of the joining area of the foamed resin that flows and merges in the direction is set lower than the foaming ratio in the other areas.

  The invention according to claim 2 is the invention according to claim 1, wherein a recess is formed on the surface of the base material corresponding to the merged region of the foamed resin, and the skin of the region corresponding to the recess is The surface is formed in a substantially uniform flat surface, and the thickness is set to be thicker than the thickness of other regions.

  The invention according to claim 3 relates to the latter molding method, wherein a molding surface at a location corresponding to a joining area of the foamed resin injected and filled in the cavity is formed on a substantially uniform flat surface. And a base material in which a recess is formed corresponding to the merged region of the foamed resin, and the base material is placed in the cavity of the molding die between the molding surface of the molding die and the surface of the base material. The foamed resin was injected and filled into the space in the cavity in a state where the space was formed, and then the vicinity of the molding surface of the molding mold of the foamed resin and the vicinity of the surface of the base material began to solidify. At that time, by expanding the cavity volume and foaming the foamed resin, the skin made of the foamed resin in which the foaming ratio of the region corresponding to the concave portion is set to be smaller than the foaming ratio of the other region is removed from the base material. Injection molding on the surface And butterflies.

  According to the first aspect of the present invention, since the expansion ratio of the foamed resin injected into the cavity is lower than that in the other areas, the foamed gas bubbles are not so large in the confluence area and are not easily broken. Therefore, when the cavity volume is enlarged, the foamed resin is sufficiently foamed to reliably follow the molding surface of the mold, and the skin with excellent surface properties is integrally injection-molded on the surface of the base material, so that the appearance is good. An improved panel with a foamed resin skin is obtained.

  According to the invention according to claim 2, since the thickness of the skin corresponding to the merged region of the foamed resin is thicker than the thickness of the skin of the other region, the foaming ratio of the foamed resin injected into the cavity is The merge area is lower than the other areas. In addition, this thickness difference is provided by forming a recess in the surface of the base material, and the surface of the skin at that location is substantially flat, so that there is no step on the surface of the skin, and the appearance is not impaired.

  According to the invention of claim 3, by simply forming a recess on the surface of the substrate and enlarging the cavity, the foaming ratio of the region corresponding to the recess is set smaller than the foaming magnification of the other region, A skin with a foamed resin skin having an improved appearance can be easily obtained by injection-molding a skin having excellent surface properties integrally with the surface of the substrate.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 3 shows an instrument panel upper panel 1 constituting the upper left half of an instrument panel for a vehicle as a panel with foamed resin skin according to an embodiment of the present invention.

  As shown in FIGS. 1 and 2, the instrument panel upper panel 1 is configured by integrally injection-molding a skin 5 made of foamed resin on the surface of a base material 3. The foamed resin which is the resin raw material of the skin 5 is described in the molding step. The gate shown by a virtual line on the right side of the upper edge of the instrument panel upper panel 1 in a state where the base material 3 is disposed in the cavity of the mold. 7 is injected and filled into the cavity of the mold (see FIG. 3).

  In this embodiment, a resin-made material is used as the base material 3. For example, a thermoplastic resin made of an olefin-based resin such as polypropylene, or a reinforcing material such as glass fiber may be mixed therein, or may be a thermosetting resin. Depending on the purpose of use, in addition to the resin, for example, a metal such as an aluminum alloy or a wood-based material such as a wood chip panel can be used. A cylindrical projecting portion 9 having a side vent air outlet 9a is integrally projected near the surface left corner of the base material 3, and between the projecting portion 9 and the left end edge of the base material 3. Has a recess 11 (see FIGS. 1 and 9). That is, the recess 11 flows into the joining region E where the foamed resin injected into the cavity of the mold spreads and flows into the cavity, hits the protruding portion 9 of the base material 3 and splits into both sides, and then merges. Correspondingly formed.

  The skin 5 is made of a thermoplastic elastomer such as urethane, olefin, polyester, and styrene, and the thermoplastic elastomer includes a chemical foaming agent that generates gas by a chemical reaction, carbon dioxide gas, nitrogen gas, and the like. Foam promoting substances such as inert gas (physical foaming agent) are mixed. The skin 5 of the region corresponding to the recess 11 of the base material 3 is formed on a substantially uniform flat surface, and the thickness T1 is set to be thicker than the thickness T2 of the other region by the depth of the recess 11. (See FIG. 9). As a result, the skin 5 is described in the molding process, and the foaming ratio of the joining area E of the foamed resin that is injected into the cavity at the time of skin molding and flows and merges in a different direction is lower than the foaming ratio of the other areas. Is set. Moreover, although the said skin 5 is represented as a single layer for the sake of drawing, it is comprised by the surface skin layer and the internal foaming layer. The skin layer has no voids and is set to have a high resin density. However, the foam layer has a large number of voids and is set to have a lower resin density than the skin layer.

  Such an instrument panel upper panel 1 is molded using a molding die 101 as shown in FIGS.

  The mold 101 includes a fixed mold 103 and a first movable mold 105 for molding the base material 3 of the instrument panel upper panel 1 (see FIG. 4). Further, a second movable mold 107 for injection-molding the skin 5 of the instrument panel upper panel 1 with the fixed mold 103 is also provided (see FIG. 5). The fixed mold 103 is formed with a molding surface 103a corresponding to the back surface shape of the instrument panel upper panel 1 (base material 3). The first movable mold 105 is formed with a molding surface 105a corresponding to the surface shape of the instrument panel upper panel 1 (base material 3). Further, a convex portion 105b for forming the concave portion 11 of the base material 3 is formed on the molding surface 105a at a location corresponding to the joining region E of the foamed resin injected and filled into the cavity (see FIG. 4). ). The second movable mold 107 is formed with a molding surface 107a corresponding to the surface shape of the instrument panel upper panel 1 (skin 5). Further, the molding surface 107a at the location corresponding to the joining area E of the foamed resin injected and filled into the cavity does not have the convex portion 105b like the first movable mold 105, and is formed on a substantially uniform flat surface. (See FIG. 5).

  First, as shown in FIG. 4, the first movable mold 105 is brought close to the fixed mold 103 and the mold 101 is closed. In this mold closed state, a cavity 109 for injection molding the base material 3 of the instrument panel upper panel 1 is formed between the molding surface 103a of the fixed mold 103 and the molding surface 105a of the first movable mold 105.

  Next, a fiber-containing thermoplastic resin R (eg, fiber-filled polypropylene resin) such as glass fiber for molding the base material 3 is injected into the cavity 109 from the injection machine (not shown) through the gate 7 (see FIG. 3). Fill. FIG. 4 shows this injection filling state.

  Thereafter, the thermoplastic resin R is solidified in the cavity 109 and the substrate 3 is molded. A cylindrical projecting portion 9 having a side vent air outlet 9 a is integrally projected near the left corner of the surface of the base material 3, and between the projecting portion 9 and the left edge of the base material 3. The recess 11 is formed corresponding to the merged region E of the foamed resin (see FIGS. 1 to 3 and FIG. 5). Then, when the base material 3 is molded, the first movable mold 105 is replaced with the second movable mold 107 while the base material 3 is left on the fixed mold 103 as shown in FIG. In this state, a space C is formed in the cavity 109 ′ of the mold 101 between the molding surface 107 a of the second movable mold 107 and the surface of the base material 7. Naturally, the space C corresponding to the concave portion 11 of the base material 3 is wider than the space C of other regions by the depth of the concave portion 11.

  Thereafter, as shown in FIGS. 6 and 7, the space C is injected and filled with foamed resin R ′ (thermoplastic elastomer) mixed with the above-mentioned expansion promoting substance from an injection machine (not shown). The foamed resin R ′ flows in the space C and flows into the space C. The foamed resin R ′ hits the protruding portion 9 of the base material 3 and splits into both sides, and then the concave portion 11 between the protruding portion 9 and the left end edge of the base material 3. That is, it merges in the merge area E. FIG. 6 shows a state immediately before the foamed resin R ′ joins at the recess 11. FIG. 7 shows a state in which the foamed resin R ′ has joined at the recess 11. A joined portion joined and joined is indicated by a symbol D.

  After that, when the foamed resin R ′ injected and filled in the space C starts to solidify, a skin layer (not shown) is formed in the vicinity of the molding surface 107 a of the second movable mold 107 and the surface of the base material 3. However, this skin layer has not completely solidified yet.

  Then, in the process of solidifying the foamed resin R ′, the cavity volume is expanded to foam the foamed resin R ′. Specifically, as shown in FIG. 8, the second movable mold 107 is retracted in the cavity volume expansion direction X (mold opening direction). At this stage, the foamed resin R ′ is cooled at an early stage due to the influence of the mold temperature and the surface temperature of the base material 3 because the portion contacting the molding surface 107a of the second movable mold 107 and the surface of the base material 3 is cooled early. A skin layer (not shown) having no resin and having a high resin density forms a surface layer. On the other hand, the inner part of the foamed resin R ′ is hardly affected by the mold temperature and is in a highly viscous gel state. Therefore, the expansion of the cavity volume causes the foamed resin R ′ to foam due to a gas generated by a chemical reaction or an inert gas, resulting in a large volume. The foamed layer has a large number of voids and a resin density lower than that of the skin layer. It becomes. As a result, the skin 5 made of the foamed resin in which the foaming magnification of the region corresponding to the recess 11 (merging region E) is set smaller than the foaming magnification of the other regions is integrally injection-molded on the surface of the substrate 3. . FIG. 9 shows a state where the molded instrument panel upper panel 1 is taken out from the mold 101.

  As shown in FIG. 8, the foaming magnification of the region corresponding to the recess 11 (merging region E) is set to be smaller than the foaming magnification of other regions, as shown in FIG. 2 The distance between the molding surface 107a of the movable mold 107 and the surface of the base material 3 is H0, and the distance between the molding surface 107a of the second movable mold 107 and the surface of the base material 3 in other regions is h0, The space between the molding surface 107a of the second movable mold 107 in the region corresponding to the recess 11 after the cavity volume expansion and the surface of the substrate 3 is H1, and the molding surface 107a of the second movable mold 107 in the other region. When the distance between the surface of the substrate 3 and the surface of the substrate 3 is h1, the expansion ratio can be expressed by the relationship of h1 / h0> H1 / H0.

  In the instrument panel upper panel 1 thus molded, the expansion ratio of the foamed resin R ′ injected and filled in the space C of the cavity 109 ′ is lower in the joining region E than in the other regions. In the merging region E, the foamed gas bubbles are not so large and difficult to break. Therefore, when the cavity volume is increased, the foamed resin R ′ is sufficiently foamed to reliably follow the molding surface 107a of the second movable mold 107, and the skin 5 having excellent surface properties is integrated with the surface of the base material 3. Thus, an instrument panel upper panel 1 with a foamed resin-skin skin having an improved appearance can be obtained.

  Further, the foaming magnification of the region corresponding to the concave portion 11 can be set smaller than the foaming magnification of the other regions simply by forming the concave portion 11 on the surface of the substrate 3 and enlarging the cavity 109 '. The sound instrument panel upper panel 1 as described above can be easily obtained.

  Further, since the thickness T1 of the skin 5 corresponding to the merged area E of the foamed resin R ′ is thicker than the thickness T2 of the skin 5 in the other areas, it is injected and filled into the space C of the cavity 109 ′. The expansion ratio of the foamed resin R ′ is lower in the merging area E than in other areas. In addition, this thickness difference is provided by forming the concave portion 11 on the surface of the base material 3, and the surface of the skin 5 at the location is substantially flat. Therefore, there is no step on the surface of the skin 5 and the appearance looks good. No damage.

  In addition, since the physical properties of the thermoplastic elastomer constituting the skin 5 have inherently excellent elasticity, a good hand feeling can be obtained.

  In this embodiment, the case where the panel with foamed resin skin is the instrument panel upper panel 1 is shown. However, the present invention is not limited to this, and can be applied to interior materials such as a vehicle door trim. It is not limited.

  The present invention is useful for a panel with foamed resin skin and a molding method thereof when foamed resin injected into a cavity joins at the time of skin molding.

It is sectional drawing in the II line | wire of FIG. It is sectional drawing in the II-II line | wire of FIG. It is a front view of the instrument panel upper panel which comprises the left side half of the upper side in the instrument panel as a panel with a foamed resin skin. It is a shaping | molding process figure which shows the state which injected and filled the thermoplastic resin for base material shaping | molding in the cavity of the shaping | molding die provided with the fixed mold | type and the 1st movable mold | type. FIG. 5 is a molding process diagram showing a state where the base material molded by the molding process of FIG. 4 is left in the fixed mold and the first movable mold is replaced with the second movable mold. FIG. 6 is a molding process diagram illustrating a state immediately before the foamed resin is injected into the cavity after the molding process of FIG. 5 is injected into the cavity. FIG. 7 is a molding process diagram showing a state where the foamed resin has joined from the molding process of FIG. 6. It is a shaping | molding process figure which shows the state which retracted the 2nd movable mold | type in the direction which a cavity volume expands after the shaping | molding process of FIG. It is sectional drawing of the state which took out the molded instrument panel upper panel from the shaping | molding die.

Explanation of symbols

1 Instrument panel upper panel (panel with foamed resin skin)
3 Substrate 5 Skin 11 Recess 101 Molding die 107a Molding surface 109 'Cavity C Space E Foamed resin merging area R' Foamed resin T1 Thickness T2 of the skin corresponding to the recess T2 Thickness of the other area

Claims (3)

A foamed resin skinned panel in which a skin made of foamed resin is integrally injection-molded on the surface of the substrate,
The above-mentioned skin is foamed resin characterized in that the foaming ratio of the joining area of the foaming resin that is injected into the cavity at the time of skin molding and flows and merges in different directions is set lower than the foaming ratio of other areas Panel with skin. In the panel with a foamed resin skin according to claim 1,
On the surface of the substrate, a recess is formed corresponding to the merged region of the foamed resin,
A panel with a foamed resin skin, characterized in that the skin of the region corresponding to the recess is formed on a flat surface having a substantially uniform surface and has a wall thickness greater than that of the other regions. A method for forming a panel with foamed resin skin, in which a skin made of foamed resin is integrally molded on the surface of the substrate,
A molding die in which a molding surface corresponding to the merged region of the foamed resin injected and filled in the cavity is formed on a substantially uniform flat surface, and a base material in which a recess is formed corresponding to the merged region of the foamed resin. And prepare
With the base material placed in the cavity of the mold so that a space is formed between the molding surface of the mold and the surface of the base material, the foamed resin is injected and filled into the space in the cavity. And
Next, when the vicinity of the molding surface of the molding mold of the foamed resin and the vicinity of the surface of the base material start to solidify, foaming of the foamed resin is performed by expanding the cavity volume to foam the region corresponding to the recess. A method for forming a panel with a foamed resin skin, wherein a skin made of a foamed resin having a magnification set smaller than the foaming magnification in other regions is integrally formed on the surface of the substrate.

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