JP3137538B2 - Mold for resin press molding with skin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for resin press molding with a skin used for manufacturing a molded product with a skin in which various skin materials are bonded to the surface of a core material layer made of a thermoplastic resin or the like. In particular, the present invention relates to a resin press-molding mold having a skin capable of effectively removing air in a cavity.

[0002]

2. Description of the Related Art In general, for interior parts of automobiles, molded articles with a skin in which various skin materials are bonded to a surface of a base material made of a thermoplastic resin or the like are frequently used. Then, a skin material is arranged between the opposing dies, the mold is clamped, and a molten synthetic resin is injected between the skin material and one of the dies to form by compression molding or the like.

When molding a skin material and a base material with such a mold for resin press molding with a skin, there is a disadvantage that a large amount of air is accumulated between the skin material and the mold when the mold is clamped. there were. This is because there is no escape route for air since the entire periphery is sealed with the skin material between the skin material and the mold. For this reason, conventionally, molding was performed by compressing the residual air by increasing the mold clamping pressure.

[0004]

However, if there is residual air in the cavity, the residual air is compressed. With the generation of the compressed air, the upper mold must be molded under a higher pressure. Therefore, not only cannot high quality products be obtained, but also the quality is not stable, the molding pressure must be increased, and the product cycle cannot be increased. If the lap allowance of the upper and lower molds is simply reduced in order to reduce the residual air, there is a disadvantage that the resin leaks out of the mold during the compression process.

[0005] For example, if the upper die is movable in the shearing member such as a press device, a groove or the like is formed in the middle of the shearing member, and air is discharged from the groove. However, the above-mentioned groove cannot be applied to the upper mold without such a configuration.

In particular, when molding a resin with a skin, the skin is easily affected by residual air, and it is necessary to discharge the residual air from the cavity until completion of the mold clamping of the upper and lower molds. In addition, applying a high pressure and forcibly holding down and molding causes looseness or partial tension of the skin material, which affects the quality.

SUMMARY OF THE INVENTION An object of the present invention is to provide a resin press with a skin capable of effectively evacuating air in a cavity, molding at a low molding pressure, improving resin filling properties, and preventing thinning and underfilling. An object of the present invention is to provide a molding die.

[0008]

Skin-covered resin press molding die according to the problem-solving means for the present invention forms a cavity in the first mold and the second mold, the first mold and the second in the mold by placing a skin material between, with skin resin press mold formed by the mold clamping and injecting molten resin between said said skin material first mold, the second In the mold, a plurality of air holes penetrating to the outside are formed in the cavity surface of the mold, and a valve provided with a cylinder device is slidably disposed in the air hole. Is characterized in that it slides in the air hole and closes the cavity surface just before the end of the mold clamping.

[0009]

The mold for resin press molding with skin according to the present invention comprises:
Forming a cavity in the first mold and the second mold, the said
By placing a skin material between the first mold and the second mold formed by mold clamping and injecting molten resin between said said table <br/> cladding material first mold in skin-covered resin press molding die, the second
In the mold 2, a plurality of air holes penetrating to the outside are formed in the cavity surface of the mold, and a valve provided with a cylinder device is slidably disposed in the air hole. the valve is configured to be to close the cavity surface by sliding the air holes in the mold clamping near the end it can be pulled out of the air in the mold from the space made by Siri <br/> Sunda over backward , And both molds can be completely sealed.

[0010] As described above, the residual air in the cavity can be effectively evacuated, the molding can be performed with a low molding pressure, the filling property of the resin can be improved, and the thinning and underfilling can be prevented.

[0011]

An embodiment of the present invention will be described below with reference to the drawings. The members, arrangements, and the like described below do not limit the present invention, and can be variously modified within the scope of the present invention.

[0012] 1 to 4 show examples of a skin-covered resin press molding die, Figure 1 is a plan view of a mold, Figure 2 is Figure 1
FIG. 3 is a sectional view showing a mold clamping operation state in a compression step, and FIG. 4 is a sectional explanatory view at the time of completion of compression.

[0013] The embodiment with skin resin press molding die is constituted by a first mold 10 and second mold 20.,
These first mold 10 and second mold 20, is disposed opposite. In this example, the first mold 10 is a fixed mold and the second mold 20 is a movable mold. A cavity K having a predetermined shape is formed by the first mold 10 and the second mold 20.

From a supply device of the molten synthetic resin J (not shown ), the molten synthetic resin J is supplied to the cavity K via a pipe and a gate (both not shown) in the first mold 10 which is a fixed mold. Is configured to be injected. Further, the apparatus of this example is configured so that cooling and the like can be performed after clamping with the first mold 10 and the second mold 20 by pressing. Known techniques can be used for the injection device and the mold clamping device of the molten synthetic resin J.

[0015] The second die 20, a plurality of air holes 51 (in this example a horizontal direction as shown in Figure 2) direction of the side surface side from the surface of the cavity K penetrates to the outside of the mold 20 is formed The air hole 51 is configured such that the air hole 51 is closed by the other mold 10 when the mold is clamped. That is, the formation position of the air hole 51 in this example is formed at a position where the air hole 51 is closed by one of the molds 10 when the mold clamping is completed. The air hole 51 is formed at a position closer to the first mold 10 than the position where the width X of the thickness of the resin material with skin is secured.

[0016] As the material of the skin material H used in the present invention, woven, nonwoven, polyolefin, polyvinyl chloride, thermoplastic resin and a polyolefin such as nylon, polyester, urethane, thermoplastic elastomer such as vinyl chloride Sheets and films. Further, the above-mentioned materials may be used alone or a laminate of two or more kinds may be used as the skin material H.

In order to give a softer feel, the skin material H
A foam or sheet of polypropylene, polyethylene, urethane, or the like is bonded to the back surface of the cloth, or a cloth or sheet for the purpose of protecting the heat from the molten resin at the time of molding or strengthening the adhesive force between the skin material H and the core material layer. A laminate bonded to the back side can also be used. In using these skin materials H, preheating may be performed prior to supply in order to adjust the tensile stress and elongation of the skin material H.

The resin used as the base material in the present invention, that is, the resin J to be injected is, for example, polypropylene,
For compression molding, injection molding and extrusion molding of thermoplastic resins such as polyethylene, polystyrene, acrylonitrile-styrene-butadiene copolymer and nylon, and thermoplastic elastomers such as ethylene-propylene block copolymer and styrene-butadiene block copolymer. Any of those commonly used can be used. In addition, those containing additives such as inorganic fillers, fillers such as glass fibers, pigments, lubricants, and antistatic agents can also be appropriately used.

[0019] Next will be described the operation of the skin-covered resin press molding die 10 and 20 having the above structure, the first not shown epidermis holding means skin material H and the first die 10 and the second die 20 The resin J serving as the base material is injected into the cavity K, and the molds 10 and 20 are clamped. In this way, as shown in FIG. 3, the residual air between the second mold 20 and the skin material H is discharged from the air holes 51 as the second mold 20 closes. Since the air holes 51 of the present example are formed leaving the width X of the thickness of the resin material with skin, which is a product, the mold clamping is completed in a state where no air remains in the cavity K, and FIG. As shown, when the mold 10 is clamped, the mold 10 is
Closed to the side.

In this embodiment, the air holes 5 extend in the side direction of the mold 20.
1 is formed, the shear edge portions of the two molds 10 and 20 are reliably brought into contact with each other, and the skin material H is formed.
Not only is the pressing of the molds 10 and 2
Since there is a wrap margin at 0, the seal is completely sealed, and even if a high pressure is applied, molding can be completed without resin leakage. It is also effective when the thickness of the base material and the skin material H is set in advance.

The resin press-molding mold with a skin shown in FIGS. 5 to 7 has an outer surface in a direction from the surface of the cavity K of one of the molds 20 to a side surface (in this example, a horizontal direction as shown in FIG. 5). Is formed with a plurality of air holes 61, and a valve 71 provided with a cylinder device 70 is slidably disposed in the air holes 61. The air hole 61 of the present example is formed in a tapered shape spreading outward. The cylinder device 70 of this embodiment has a valve 71 at the tip of a rod 72, and the valve 71 is formed in a tapered shape so as to match the tapered shape of the air hole 61.

In the state of the start of the mold clamping, the cylinder device 70 keeps the rod 72 in a short retracted position so that the air hole 61 is released to the outside, and the air existing in the mold by the mold clamping is set. To discharge. In the mold clamping step near the completion of mold clamping, the rod 72 is extended, and the valve 71 slides in the air hole 61 to close the surface of the cavity K.

From the air holes 61 thus formed in the mold,
The air is discharged, and before the compression is completed, the valve 71 is closed at a timing at which the resin does not leak. Thereby, the cylinder device 7
The air inside the mold can be evacuated from the space created by the retraction of zero, and both molds 10, 20 can be completely sealed. In this embodiment, the timing of closing the valve 71 differs depending on the product shape and the resin characteristics. Therefore, similarly to the above-described embodiment, the timing can be set by a timer or a position sensor, which is a known or well-known technology, and operated to optimize the operation.

[0024]

As described above, according to the present invention, the mold
Residual air in the tee can be effectively removed, molding can be performed at a low molding pressure, resin filling can be improved, thinning and underfilling can be prevented, and skin deformation (ie, air pockets) can occur. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a plan view of a mold.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view showing a mold clamping operation state in a compression step.

FIG. 4 is an explanatory sectional view at the time of completion of compression.

FIG. 5 is an operation explanatory view showing an example using a valve.

FIG. 6 is an operation explanatory view showing an example using a valve.

FIG. 7 is an operation explanatory view showing an example using a valve.

[Explanation of symbols]

Reference Signs List 10 first mold 20 second mold 70 cylinder device 71 valve 72 rod K cavity 61 air hole J synthetic resin H skin material

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 43/18-43/20 B29C 43/32-43/42 B29C 33/10-33/12 B29C 33/42

Claims (1)

(57) [Claims] 1. A forming a cavity in the first mold and the second mold, by placing a skin material between said first mold and the second mold, wherein the said surface material In a resin press-molding mold having a skin formed by injecting a molten resin between first molds and clamping the mold, the second mold includes a plurality of molds penetrating to the outside of a cavity surface of the mold. An air hole is formed, and a valve provided with a cylinder device is slidably disposed in the air hole, and the valve slides inside the air hole just before the end of the mold clamping in the mold clamping step to remove the cavity surface. A resin press molding die with a skin, which is closed.