JP3163897B2 - Method for molding resin products and molding apparatus - 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 for molding a resin product, such as an instrument panel for an automobile, in which a sheet material is partially heat-sealed to the surface of a substrate body, and a mold for molding the resin product. It concerns the device.

[0002]

2. Description of the Related Art In general, an instrument panel (hereinafter referred to as "instrument panel") comprises a base made of a hard resin and an elastic sheet material attached to the surface thereof.
Due to its structure, the instrument panel is a "full pad type" in which an elastic sheet material is provided on the entire surface, a "half pad type" in which a part of the base material is exposed, and a "padless type" consisting only of the base material ] Are roughly divided into three types.

For example, as shown in FIG. 10, a base material 52 of a "half pad type" instrument panel 51, which is often used in a public car, is required to have a predetermined rigidity and formability, so that ABS (acrylonitrile) is used. -Butadiene-styrene), PP (polypropylene) and the like. The elastic sheet material 53 is made of, for example, a cushion layer 54 made of a flexible polyurethane foam,
A skin layer 55 made of (polyvinyl chloride) is provided.

The instrument panel 51 is formed, for example, as follows. That is, the elastic sheet material 53 is previously formed into a predetermined shape by known vacuum forming or the like. Next, the elastic sheet material 53 is set at a predetermined position in a cavity of a mold device for molding the base material 52. And
The plasticized resin material is injected and filled into the cavity through a plurality of gates. Then, the base material 52 is formed of the resin material, and the elastic sheet material 53 is thermally fused to the surface thereof. Thereafter, the above-mentioned instrument panel 51 is taken out by opening the mold.

[0005]

However, in the above technique, the length and width of the instrument panel 51 are very large with respect to the thickness. For this reason, in order for the resin material in the cavity to spread to the end,
It was necessary to apply a very large pressure and the injection time was prolonged. As a result, the high pressure and the long injection time may cause the elastic sheet material 53 to be damaged.

In order to reduce the above-mentioned problems, it is conceivable to increase the number of gates. However, in such a case, the production cost has been significantly increased. The present invention has been made in order to solve the above problems, and an object thereof is to produce a resin product having a base material body and a sheet material heat-sealed to the surface of the base material body. A method of molding a resin product and a mold for molding the same, which can prevent the sheet material from being damaged due to a long injection time and can prevent an increase in cost due to an increase in the number of gates. It is to provide a device.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a base material body made of a resin material, and a sheet material thermally fused to a part of the surface thereof. A method for forming a resin material, comprising: forming the sheet material by a vacuum forming method to have a predetermined shape; and a partly set surface on which the sheet material is set, wherein the base material A first mold having a first molding surface for forming a part of the main body, and a first mold which is disposed so as to be able to approach and separate from the first mold to form a remaining part of the base body. And a second mold having a groove for forming a continuous convex channel across substantially both ends of the base body. And the step of making the surface of the sheet material substantially contact the set surface of the first mold Setting the sheet material in a cavity formed by the first molding surface and the second molding surface; and providing the plasticized resin material to at least the second mold provided in the second mold. A step of injecting the gas into the cavity from one gate and filling the same; a step of injecting a gas into the groove at substantially the same time as the step of injecting the gas so that the gas passes through the groove; The method further includes a step of opening the mold and the second mold, and taking out the base material body having the sheet material thermally fused to a part of the surface from the mold apparatus.

Further, in the invention according to claim 2,
A base material body made of a thermoplastic resin and having a convex channel that is continuous between substantially both ends on the back surface, and a sheet material that is thermally fused to a part of the base body surface. A mold device for molding a resin product comprising: a first molding surface for forming a part of the base material body, the mold device having a set surface on which the sheet material is set in a part A first mold having a first mold and a first mold which is provided so as to be able to contact and separate from the first mold and forms a cavity for forming the base material body by alignment with the first molding surface. A second mold having a second molding surface, a groove for forming the channel, and a gate for injecting a resin material into the cavity; Gas press-fitting means for pressurizing gas into the groove so as to allow gas to pass therethrough And as its gist further comprising a.

[0009]

According to the first aspect of the present invention, first, a sheet material is formed into a predetermined shape by a vacuum forming method. A first mold having a first molding surface; and a second mold having a second molding surface, which is disposed so as to be relatively movable toward and away from the first mold. Is prepared. Further, the sheet material is set in the cavity formed by the first molding surface and the second molding surface while the surface of the sheet material is substantially in contact with the setting surface of the first mold.

Then, the plasticized resin material is used as the second material.
Is injected and filled into the cavity from at least one gate provided in the mold. Almost simultaneously with this injection step, gas is press-fitted into a groove provided in the second mold,
Gas passes through the groove so as to pass through the resin material. Thereafter, the first and second molds are opened, and the base material body having the sheet material thermally fused to a part of the surface is taken out of the mold apparatus. By going through the above series of steps, and made of a resin material, a base body having a convex channel continuous on both sides substantially across the back surface,
A resin product comprising a sheet material thermally fused to a part of the surface is molded.

In the present invention, gas is injected into the groove almost simultaneously with injection of the resin material, and the gas passes through the groove so as to pass through the resin material. At this time, the resin material is pulled by the passage of the gas, so that the resin material is smoothly filled all over the cavity. Therefore, the injection pressure does not increase so much and the injection time is shortened.

According to the second aspect of the present invention, first, the sheet material is set on the setting surface of the mold. Further, a cavity is formed by the alignment between the first molding surface of the first mold and the second molding surface of the second mold that is disposed so as to be able to approach and separate from the first mold. You. Then, the plasticized resin material is injected into the cavity through a gate provided in the second mold. As a result, a resin product comprising a base material body made of a thermoplastic resin and having a convex channel on the back surface side and a sheet material thermally fused to a part of the base material body surface is obtained. Can be

Also in the present invention, the gas injection means
Almost simultaneously with the injection of the resin material, the gas is press-fitted into the groove provided in the second mold. For this reason, an operation almost equivalent to that of the first invention is provided.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will now be described with reference to FIGS.
7 will be described. As shown in FIG. 2, an instrument panel (hereinafter referred to as “instrument panel”) 1 as a resin product around an instrument panel is disposed in front of a driver's seat and a passenger seat of an automobile. The instrument panel 1 includes a substrate body 2
And an elastic sheet material 3 attached to an upper surface thereof (a hatched portion in the figure). That is, the instrument panel 1 of the present embodiment is of a “half pad type” which is often used in public cars, and a part of the base material body 2 is exposed.

As shown in FIG. 3 and FIG.
Is made of polypropylene mixed with filler (PP with filler), and has a predetermined rigidity. The elastic sheet material 3 is arranged in order from the inner layer side (the lower side in the figure).
A heat sealing layer 4 made of PP, located outside (upper side in the figure) of the heat sealing layer 4, a cushion layer 5 made of PP foam and located outside the cushion layer 5, and made of polyvinyl chloride (PVC) The solid skin layer 6 is integrally formed. In this embodiment, the heat-sealing layer 4 of the elastic sheet material 3 is bonded to the upper surface of the base body 2 by heat-sealing, so that the elastic sheet material 3 and the base body 2 Adhesion is ensured.

The base body 2 is integrally formed with a channel 7 protruding toward the back side (left side in the figure). In this embodiment, the channel 7 is formed so as to be continuous between substantially both ends of the instrument panel 1, and a hollow portion 8 is formed therein. This hollow part 8
Is a trace of press-fitting of a gas formed at the time of molding the base body 2 described later.

Next, the mold apparatus 11 for molding the base body 2 of the instrument panel 1 will be described. As shown in FIG. 5, the mold apparatus 11 includes a fixed mold 12 constituting a first mold and a movable mold 13 constituting a second mold. The fixed mold 12 is provided so as to be able to approach and separate from the movable mold 13. In addition, the fixed die 12 includes a first molding surface 14 for forming a part of the base body 2,
It has a setting surface 15 on which the elastic sheet material 3 is set. Further, the movable mold 13 has a second molding surface 16. Then, the fixed mold 12 and the movable mold 13 are in contact with each other, and the first molding surface 14 and the second molding surface 16 are aligned to form a cavity 17 for forming the base body 2. You. In addition, in the present embodiment, a plurality of (only one is shown in the figure) gates 21 that open to the cavity 17 are formed in the movable mold 13. These gates 21 are open toward the set surface 15.

The movable die 13 has a groove 22 for forming the channel 7. Further, a gas press-fitting means for press-fitting a gas into the groove 22 is provided on the movable mold 13 and the outside thereof, and a nozzle forming a part of the gas press-fitting means is provided at a portion opened to the groove 22. 31 are provided.

Next, in the present embodiment, the instrument panel 1
A method of manufacturing the device will be described. First, the elastic sheet material 3 is manufactured in advance. That is, a planar sheet having the above three-layer structure is obtained. Next, the instrument panel 1 is formed into a shape following the shape of the upper surface of the instrument panel 1 by a known vacuum forming method. Thereafter, excess portions are cut and removed by trimming. Through these series of steps, the elastic sheet material 3 is obtained.

Then, as shown in FIG. 6, the previously formed elastic sheet material 3 is set at a predetermined position in the cavity 17 of the mold apparatus 11. More specifically, the elastic sheet material 3 is brought into contact with the set surface 15 of the fixed mold 12 in a state where the molds 12 and 13 are opened, and then the fixed mold 12 is brought into contact with the movable mold 13. At this time, the elastic sheet material 3 is set in a state where the solid skin layer 6 is in contact with the setting surface 15.

Subsequently, as shown in FIG. 1, the plasticized filler-containing PP (resin material) is injected from the injection molding machine into the cavity 17 through the gate 21 using an injection molding machine (not shown). . Almost simultaneously with this injection,
The gas injecting means is operated to inject gas into the groove 22 through the nozzle 31. Then, as shown in the figure, the gas flows in the groove portion 22 so as to pass through the resin material, and at the same time, flows in the cavity 17 as the resin material is pulled along with the flow of the gas. Then, as shown in FIG. 7, the resin material is filled in the cavity 17.

At this time, the heat fusion layer 4 is softened by the heat of the resin material. Thereafter, the resin material is cooled and solidified, so that the heat-fusion layer 4 is fused with the resin material. By this fusion, the elastic sheet material 3 and the resin material (base body 2) are joined. Then, the molds 12 and 13 are opened, and the base body 2 to which the elastic sheet material 3 is attached is taken out, so that the instrument panel 1 in which the channel 7 is integrally formed on the back surface of the base body 2 is provided. can get.

In the instrument panel 1 thus obtained, a predetermined rigidity is ensured by the base body 2 made of the filler-containing PP. In addition, the cushion layer 5 of the elastic sheet material 3 attached to a part of the base body 2 ensures a soft feeling when touched, and the solid skin layer 6 provides anti-glare property, weather resistance, heat resistance, Appearance quality etc. are ensured. Furthermore, the adhesiveness between the elastic sheet material 3 and the base material body 2 is ensured by the heat sealing layer 4.

Further, in the present embodiment, the injected resin material flows quickly in the cavity 17 so as to be pulled along with the flow of the gas, so that the resin material is smoothly filled up to every corner of the cavity 17. Becomes Therefore, the injection pressure does not increase so much and the injection time is shortened.
FIG. 8 is a graph showing the relationship between the injection time and the injection pressure for explaining the effect of the present embodiment. As shown in the figure, in the prior art, the injection pressure increases in a quadratic curve with the lapse of time because the pressure loss increases toward the end of the cavity. On the other hand, in the present embodiment, the resin material can be injected in a short shot by press-in of the gas, and an increase in the injection pressure can be prevented. Further, the injection filling time into the cavity 17 can be made shorter than before. Therefore, it is possible to reliably suppress the elastic sheet material 3 from being damaged due to a high injection pressure and a long injection time,
In addition, since it is not necessary to increase the number of gates 21, an increase in cost can be prevented.

The present invention may be implemented as follows, with a part of the configuration being appropriately changed. (1) Although the description is omitted in the above embodiment, a tab space portion 41 for forming a discarded meat (tab) may be provided in the mold device 11 at the end of the cavity 17. With such a configuration, an increase in the pressure in the cavity 17 at the end of the cavity 17 can be reliably suppressed, and the injection pressure of the resin material and the gas injection pressure can be further reduced.

(2) In the above embodiment, the base material body 2 is made of PP containing filler, but may be made of only PP. Further, it may be made of a thermoplastic resin (for example, an ABS resin or the like) having a predetermined rigidity at the time of solidification.

Further, in the above embodiment, the elastic sheet material 3
Is composed of the heat-sealing layer 4, the cushion layer 5, and the solid skin layer 6, but may be formed of any number of layers as long as the material can be used as the skin, and the material is not limited at all. is not. Therefore, a sheet material having only the skin layer without the cushion layer 5 may be used.

(3) The movable mold 13 and the fixed mold 12 in the above embodiment may be turned upside down in the drawing.
(4) In the above embodiment, the instrument panel 1 is employed as a resin product. However, the instrument panel 1 may be embodied as a resin product such as a door trim, a side garnish, or a pillar garnish.

(5) In the above embodiment, the channel 7 is provided at a plurality of locations. (6) A part of the channel 7 in the above embodiment can be cut to have a desired shape and a desired size. It is not described in each claim of the claims,
The technical ideas that can be grasped from the above embodiment will be described below together with their effects.

(A) In the resin product manufacturing method or the molding die apparatus according to claim 1 or 2, the base body and a portion of the sheet material that abuts on the base body are both It is characterized by using the same material as a main component. With such a configuration, it is possible to improve the joining force between the two.

(B) The method for manufacturing a resin product or the mold apparatus for molding according to claim 1 or 2, or the above-mentioned supplementary note (a), wherein the mold apparatus includes a resin material and a gas from an end of a cavity. A space is provided to allow the accommodation of With this configuration, the injection pressure and the gas injection pressure can be further reduced.

[0032]

As described above in detail, according to the first or second aspect of the present invention, a high injection performance is required for manufacturing a resin article having a base material body and a sheet material heat-sealed on its surface. It is possible to prevent the sheet material from being damaged due to the pressure and the long ejection time, and it is possible to prevent an increase in cost due to an increase in the number of gates.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view illustrating a mold apparatus according to an embodiment of the present invention, in which a resin material is injected and a gas is injected.

FIG. 2 is a perspective view of an instrument panel in one embodiment.

FIG. 3 is an enlarged cross-sectional view of the instrument panel in one embodiment.

FIG. 4 is a sectional view taken along line AA of FIG. 3 in one embodiment.

FIG. 5 is a partial sectional view showing a mold apparatus for molding an instrument panel in one embodiment.

FIG. 6 is a cross-sectional view showing a state in which an elastic sheet material is set inside a mold apparatus for instrument panel molding in one embodiment.

FIG. 7 is a partial cross-sectional view of a mold apparatus showing a state in which a cavity is filled with a resin material in one embodiment.

FIG. 8 is a graph showing the relationship between the injection pressure and the passage of time in one embodiment.

FIG. 9 is a partial sectional view of a mold apparatus according to another embodiment of the present invention.

FIG. 10 is an enlarged sectional view showing a part of an instrument panel according to a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Instrument panel (instrument panel) as a resin product, 2 ... Substrate main body, 3 ... Elastic sheet material as a sheet material, 7 ... Channel, 11 ... Mold apparatus, 12 ... Fixing as a 1st mold Mold, 13 ... movable mold as second mold,
14: first molding surface, 15: setting surface, 16: second molding surface, 17: cavity, 21: gate, 22: groove,
31 ... Nozzle constituting gas injection means.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-53428 (JP, A) JP-A-5-147067 (JP, A) JP-A-62-212114 (JP, A) JP-A-4- 308711 (JP, A) JP-A-2-103108 (JP, A) JP-A-3-244516 (JP, A) JP-A-2-47023 (JP, A) JP-A-5-64824 (JP, A) JP-A-2000-296538 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 45/00-45/84

Claims (2)

(57) [Claims] 1. A method for molding a resin product comprising a base material body (2) made of a resin material and a sheet material (3) heat-sealed to a part of the surface thereof. 3) forming the sheet material (3) into a predetermined shape by a vacuum forming method;
5) and a first mold (12) having a first molding surface (14) for forming a part of the base body (2).
And the first mold (12) is disposed so as to be able to approach and separate from the first mold (12),
A second for forming the rest of the substrate body (2);
A second mold (2) having a molding surface (16) and a groove (22) for forming a continuous convex channel (7) substantially across both ends of the base body (2). 13) a step of preparing a mold apparatus (11) comprising: a sheet material (3) in a state where the surface of the sheet material (3) is substantially brought into contact with the set surface (15) of the first mold (12); Setting the sheet material (3) in a cavity (17) formed by the first molding surface (14) and the second molding surface (16); A step of injecting and filling the cavity (17) from at least one gate (21) provided in the second mold (13), and substantially simultaneously with the step of injecting gas into the groove (22). By press-fitting, the gas passes through the groove (22). The first mold (12) and the second mold (13) are opened, and the base material body (3) on which the sheet material (3) is thermally fused to a part of the surface. 2) taking out from the mold apparatus (11). 2. A base body (2) made of a thermoplastic resin and having, on a back surface thereof, a convex channel (7) continuous substantially across both ends, and a front surface of the base body (2). And a sheet material (3) heat-sealed to a part of the resin material (1), wherein the sheet material (3) is set in a part. Set surface (1
5) and a first mold (12) having a first molding surface (14) for forming a part of the base body (2).
And a cavity (17) arranged to be able to approach and separate from the first mold (12) to form the base body (2) by alignment with the first molding surface (14). A second molding surface (16), a groove (22) for forming the channel (7), and a gate for injecting a resin material into the cavity (17). A second mold (13) having (21), and a gas passing through the groove (22).
And a gas press-fitting means for pressurizing a gas into the groove (22).