JP3822208B2 - Vacuum forming method and vacuum forming machine for interior parts - Google Patents

Description

  The present invention sets a base material in which air intake passages are dispersedly formed in a vacuum suction type corresponding to the shape, sets a skin material in which a foam layer is bonded to the skin, and sets the skin material on the surface of the base material. The present invention relates to a vacuum forming method and a vacuum forming machine for interior parts for producing interior parts such as automobile door trims, instrument panels and the like by adhering them to each other by vacuum suction.

  An instrument provided with a case-like defroster housing portion 12a and an integrally formed airbag door 7 that allow the defroster 8 similar to that shown in FIG. A vacuum bonding process for manufacturing the panel 9A will be described with reference to FIG. In this instrument panel, for example, a skin material 3 in which a foam layer 2 made of PP foam (polypropylene foam) is bonded to a skin 1 made of TPO (thermoplastic olefin) is bonded to a plate-like base material 4 in three layers. It has been produced. At the time of integral molding, the skin material 3 is manufactured by vacuum suction with a vacuum suction mold in a warmed and softened state (FIG. A). At that time, a defroster housing portion 2a having a convex undercut portion 2b corresponding to the shape of the defroster 8 having the engagement groove 8a is formed by the vacuum suction type mold surface shape. On the other hand, the base material 4 is injection-molded, for example, made of PP (polypropylene), and the intake passage is dispersedly formed by post-processing perforations, and is set on the convex die 5a of the vacuum suction die 5 (B in the figure). The base material 4 is formed with a defroster storage portion 4a corresponding to the defroster storage portion 2a.

  Next, the base material 4 is sprayed with an adhesive, and the skin material 3 is set and evacuated as shown in FIG. The instrument panel 9A is manufactured. At that time, as shown in FIG. 6A, the foamed layer 2 is deformed into a convex shape along the undercut portion 2b during the vacuum molding of the skin material 3 and is not adhered to the base material 4 in the defroster storage portion 4a. The hollow portion 2c is formed, which may cause peeling, the skin 1 may be deformed, or a line may be generated. Further, the defroster 8 may be easily deformed and detached when the defroster 8 is attached to the storage portion.

  In Reference 1, a skin material is flattened and supported by a support tool, and a three-dimensional breathable substrate is assembled to a vacuum adhesive convex surface, and a fabric material is attached to a vacuum adhesive convex surface. Assemble to a partially similar receiving mold surface, and move the substrate vacuum bonding mold and the receiving mold assembled with the fabric material from both sides to the heated and softened skin material with a support, and the skin material Discloses a method for producing a part-distributed vehicle interior member in which a fabric material is pressed and bonded to a predetermined portion of a skin material in a vacuum-bonding process on a surface of a substrate with a vacuum bonding type. According to this method, the fabric material is not only partially distributed on the skin material, but is also bonded to the surface of the substrate in a softened state without being molded in advance. However, it is impossible to form the undercut portion 2b only with the skin material. Therefore, in order to prevent peeling and deformation of the undercut portion 2b or to secure the engaged state of the defroster 8 after manufacture, as shown in FIG. When it is going to form the protrusion part 4b to a horizontal direction with respect to a direction, it is necessary to provide a slide core under this undercut part in an injection molding machine so that mold release is possible.

Therefore, for the purpose of eliminating such a movable mold, according to Patent Document 2, an adhesive is applied to adhere the skin material in a close contact state without leaving a hollow portion in the core material or base material having the undercut portion. The core material is set in the male mold, and the skin stretched between the male mold and the female mold is brought into contact with the core material by moving relatively to the female mold side, and vacuum suction is performed from the female mold side, Next, a vacuum forming method is proposed in which the vacuum suction is stopped and then vacuum suction is performed from the male mold side.
Japanese Patent Laid-Open No. 10-34741 JP-A-6-34433

  However, the vacuum forming according to Patent Document 2 allows the skin to adhere to the irregularities on the outer surface of the base material by sucking from both male and female molds, and the skin surface can also be shaped. Adhesive adhesion to unevenness such as the undercut portion of the peripheral wall is impossible, and in any case, an additional configuration is required for the vacuum forming machine.

  Further, the foam layer 2 of the corner portion as shown in the circle A portion of FIG. 5 is pulled to both sides at the time of vacuum suction, so that the spring bag amount after demolding is relatively reduced as shown in FIG. 6C. Therefore, there is a problem that so-called R sagging occurs. Further, when a step is generated on the surface of the base material 4, a corresponding step may also be generated on the skin 1. As shown in FIG. 6D, this step also occurs, for example, when the base material door portion 4c that is softer than the general surface is set in the airbag door 7 so as to facilitate breaking and opening. There is a possibility that a level difference will remain to some extent.

  In view of these points, the present invention provides an interior product that enables the surface of a skin material to be shaped into a desired shape with respect to the surface of the base material when the softened skin material is vacuum bonded to the base material. An object is to provide a vacuum forming method and a vacuum forming machine for carrying out this method.

In order to achieve this object, according to the present invention, according to claim 1, vacuum suction is applied to an injection-molded base material having a corner portion that is formed in a distributed manner and has a corner portion that bends in a direction crossing the die-cutting direction. In the vacuum forming method for interior parts, which is set in a mold, the skin material with a foam layer is set on the surface of the base material, and the skin material is adhered to the base material by vacuum suction to produce an interior product. The vacuum suction mold for the base material is provided on one of the two sides in the vertical direction with respect to the thermoplastic skin material supported in a flat shape, and the surface shape of the entire skin material to be shaped to the flat shape on the other side. A vacuum suction mold for the skin material having a corresponding mold surface is provided in an opposing state, and the shape of the vacuum suction mold for the skin material is based on a gap that compresses the skin material by about 20% to 50% when the mold is clamped. is formed so as to be able to set up between the surface of the wood, the skin material pressurized In a state of being softened by processing, a substrate vacuum suction type and the skin material for a vacuum suction type and clamping, by vacuum suction from both sides in these clamping state by vacuum suction type, the substrate a foam layer In addition to bonding, the skin material is shaped along the surface of the vacuum suction mold for the skin material.

With the skin material being softened, the vacuum suction mold for the base material and the vacuum suction mold for the skin material are clamped and vacuum suctioned respectively, so that the back surface of the foam layer is made into a vacuum suction mold for the base material with an adhesive. Adhered to the set substrate by vacuum suction, and the skin material is vacuum suction for the skin material in a state where the foam layer is compressed 20% to 50% by the vacuum suction mold surface of the skin material. It is adsorbed by mold vacuum and shaped. At this time, by utilizing the softness of the skin material and facilitating demolding, according to claim 2, the undercut portion is formed in the skin material without forming the shape to be compressed by 20% to 50%. In addition, a recess is formed in a direction intersecting with the direction of removing the vacuum suction type for the skin material . In order to eliminate the need for a solvent-type adhesive application step, a hot-melt adhesive is laminated on the back surface of the foamed layer.

In order to surely avoid the generation of wrinkles at the corner portion, the foam layer is formed in the corner portion of the base material in a shape that is not similar to the corresponding corner portion of the vacuum suction mold surface for the skin material. A biting portion is formed which bites into the wall and reduces its thickness.

According to claim 5 , the vacuum forming machine for carrying out such a vacuum forming method is an injection-molded base material in which the intake passages are dispersedly formed and the surface has a corner portion that bends in a direction crossing the die-cutting direction. In the vacuum molding machine for interior products for producing interior products by adhering the skin material with foam layer to the base material by vacuum suction, it was supported in a flat shape A clamping device that clamps the periphery of the thermoplastic skin material and a heater that softens the clamped skin material by a heating process, and a vacuum suction mold for a substrate is provided on one of the upper and lower sides of the clamping device. On the other hand, a vacuum suction mold for skin material having a mold surface corresponding to the surface shape of the entire skin to be shaped with respect to the flat shape is provided in an opposed state, and the shape of the vacuum suction mold mold surface for the skin material is When clamping It is formed a clearance for compressing the skin material 20% to 50% so as to set up between the surface of the base material, skin material for vacuum suction type this skin material for vacuum suction type and the base material for a vacuum suction type, a vacuum simultaneously A suction means for performing suction is provided.

To shape the skin material surface into a desired shape to the substrate surface by claim 6, and the shape of the mold surface and the substrate surface for the skin material vacuum suction type, partially mutually dissimilar The undercut portion is formed in the skin material without forming the shape to be compressed by 20% to 50% on the surface of the vacuum suction mold for the skin material according to claim 7. As described above, the concave portion is formed in a direction crossing the demolding direction of the vacuum suction type for the skin material in a shape that is not similar to the shape of the facing substrate surface.

According to the invention of claim 1 or claim 5, since the pre-process of the vacuum forming of the skin material becomes unnecessary, and the skin is shaped along the mold surface of the vacuum suction mold for the skin material, the surface quality Not only is improved, but also there are fewer restrictions on the design, and the substrate surface can be formed in a non-similar shape. Due to the compression of the skin material during mold clamping, the transfer of the wrinkles is performed reliably, and by setting the degree of compression, compression wrinkles due to the shrinkage of the foam layer at the corner, crushing wrinkles at the time of demolding, etc. may occur. It can be easily avoided. In this case, according to the invention of claim 2, the undercut portion is formed without being deformed by bidirectional suction. According to the invention of claim 3, the solvent-type adhesive application step which is environmentally undesirable is not required at the time of integrally molding the skin material on the base material. According to the fourth aspect of the present invention, the occurrence of compression wrinkles or crushing wrinkles at the corners is reliably avoided.

According to the invention of claim 6, even if the mold surface of the vacuum suction mold for the skin material is formed in a shape that is not similar to the shape of the surface of the base material, the shaping along the mold surface is possible, According to the seventh aspect of the invention, the undercut portion is formed in a non-similar shape transverse to the clamping direction regardless of the shape of the base material by utilizing the softness of the skin material that can be removed.

  1 and 2, the same or equivalent parts as those described above for the vacuum forming machine for carrying out the vacuum forming method for interior parts according to the embodiment of the present invention will be described with the same reference numerals. The plate-like interior product to be vacuum-bonded is the same instrument panel 9 including the defroster housing portion 12a and the airbag door 7 described above with reference to FIG. As a vacuum forming machine for integral molding, a vacuum suction die 5 for the base material 4 is provided on the lower side of the clamp tool 18 for clamping the peripheral portion so as to pull and support the skin material 10 in a flat shape, and the upper side. Is provided with a vacuum suction die 16 provided with a porous concave die 16a by electroforming having a die face corresponding to the surface shape of the instrument panel 9 and facing the convex portion 5a. The vacuum suction mold 5 for the base material, which is a male mold, and the vacuum suction mold 16 for a skin material, which is a female mold, are moved up and down toward the clamp tool 18 by an attached lifting device (not shown). , 17a are concavo-convexly connected to perform clamping. Heaters 19 for heating the skin material 10 from both sides are arranged on both sides of the clamp tool 18, and can be moved to a side escape position during mold clamping.

  A thermoplastic skin material 10 has a foam layer 12 made of PP foam welded to a skin 11 made of TPO, and a hot-melt olefin-based adhesive 13 applied to the back surface thereof (FIG. 1A). Has been stored. The base material 4 is made of PP, for example, and has a peripheral wall for housing the defroster 8 and a defroster housing portion 4a which is an opening with a bottom surface portion, a base material door portion 4c for the airbag door 7, and a dispersed intake passage (not shown). 2) is injection molded. It is also conceivable to thermally laminate an olefin-based hot melt film on the back surface of the foam layer 12. The suction path (not shown) of the convex mold 5a communicating with the above-described suction path of the substrate 4 and the suction port 16d of the vacuum suction mold 16 are respectively connected to a vacuum pump and suction means for simultaneously performing vacuum suction. It is composed.

  The mold surface 16b of the concave mold 16a corresponds to the surface shape of the entire skin 11 to be shaped from a flat shape, and the general surface occupying most of the mold surface 5b of the convex mold 5a or the surface of the substrate 4 is similar. Although it has a shape, it is provided with a convex mold surface portion 16e having a concave portion 16c corresponding to a convex undercut portion 12b described later with respect to an engagement groove 8a on the outer peripheral surface of the defroster 8, a register or the like. Correspondingly, the convex mold 5a is formed with a concave mold surface portion 5c corresponding to the defroster housing 4a. That is, the mold surfaces 5b and 16b of the convex mold 5a and the concave mold 16a form a cavity that can be pressed against or substantially in contact with the base material 4 and the skin material 10 in a clamped state, but face the concave section 16c. The peripheral wall of the concave mold surface portion 5c is flat, so that the opposed portions are spaced apart and have a non-similar shape.

  As shown in FIG. 1, for the corner portion C1 on the side surface side of the instrument panel 9, the corresponding portion of the mold surface 16b is formed into a curved surface with a curvature radius of about 1 mm so as to have a roundness with a curvature radius of about 1 mm. On the other hand, the corresponding part of the base material 4 is not formed into a curved surface, the thickness of the skin 11 is 1 mm, the thickness of the foamed layer 12 before clamping is 4 mm, and the thickness of the base material 4 is in the demolding direction. On the other hand, a biting portion 4d that is gradually thickened in the orthogonal direction and thickened in the demolding direction at the end surface 4f by about 2 mm at maximum is formed, and has a non-similar shape in the facing region of the mold surface 16b.

  Similarly, as shown in FIG. 1B, in the corner portion C2 around the opening of the defroster storage portion 4a, the corresponding portion of the mold surface 16b is formed at a substantially right angle, while the corresponding portion of the base material 4 is the base portion. The thickness of the material 4 is gradually increased to form a biting portion 4e that is thicker in the demolding direction at the end surface by about 2 mm at the maximum, approaching the skin side, and narrowing the gap with respect to the mold surface 16b from 5 mm.

  When the skin material 10 is integrally formed on the base material 4, the skin material 10 having a required size is supported in a flat shape by the clamp tool 18, and the base material 4 is formed in the mold surface shape of the vacuum die 5 along the back surface thereof. Set to the convex 5a (FIG. 1B). Next, the skin material 10 is heated by the attached heater 19 to be softened. Subsequently, the heater is released and the vacuum suction mold 5 and the vacuum suction mold 16 are moved up and down to be clamped, and the suction passages (both not shown) communicate with the suction passages of the suction port 16d and the base 4 of the convex mold 5a. )) Vacuum suction from both sides almost simultaneously.

  As a result, the foamed layer 12 is adhered to the base material 4 by the hot melt type olefin adhesive 13 and the skin 11 is closely adsorbed by the mold surface 16b of the porous concave mold 16a over the entire area. The thermally softened foamed layer 12 is shaped along the mold surface 16b while being compressed or expanded, and an instrument panel 9 having an all-olefin three-layer is manufactured.

  At the time of mold clamping, as shown in FIG. 2A, in the defroster storage portion 12a, the skin material 10 is bent along the recess 16c and tries to generate cavities on both sides thereof, but by vacuum suction from both the front and back sides, Due to the tensile displacement of the skin 11 and the compression or expansion of the foam layer 12, the cavity is absorbed and a convex undercut portion 12b is formed along the concave portion 16c as shown in FIG. When the vacuum suction mold 16 is demolded after cooling, the undercut portion 12b is compressed and bent to allow demolding. As shown in Fig. C, for example, the R sagging of the corner portion of the meter storage portion 9a is also eliminated by being formed in contact with the mold surface 16b, and as shown in Fig. D, the base of the airbag door 7 is eliminated. The influence of the level difference of the material door portion 4c is also eliminated by the absorption of the foam layer 12.

As for the corner portions C1 and C2, when the surface of the base material 4 is curved in a shape similar to the mold surface 16b by a normal method, as shown by a dotted line in FIG. In C1, the gap between the corresponding corner portion of the base material 4 and the corresponding corner portion of the mold surface 16b is widened, so that the skin 11 is stretched, and the foamed layer 12 is correspondingly expanded and the rigidity is lowered, so that suction is reduced. There is a possibility that the wrinkle 9c is generated in a streak shape as shown by the dotted line in the contraction phenomenon after the stop. Similarly, wrinkles 9d are also generated at the corner portion C2 of the defroster storage portion 12a. Such wrinkles can be avoided by reducing the thickness of the foam layer 12 or increasing the radius of curvature of the corner portion, but the wrinkle tends to be more easily generated as the foam layer 12 becomes thicker . As shown by the solid line in Fig . B , wrinkles can be prevented from occurring by thinning the foam layer 12 of the corner portions C1 and C2 by the biting portions 4d and 4e into the foam layer 12 and ensuring its rigidity. become.

  In addition, as shown to the same figure E, the biting part 4g may protrude diagonally toward the type | mold surface 16b which faces, and may protrude only in the orthogonal direction with respect to a demolding direction. As shown in Fig. F, when the undercut portion 4k is provided at the front portion of the instrument panel side surface 9b to allow demolding by the compression of the foam layer 12, it is reversed in the demolding direction due to the shaving at the time of demolding. Convex wrinkles may occur at the corners. In such a case, if the biting portion 4h is similarly projected in the orthogonal direction, it is possible to limit the degree of squeezing like the foamed layer 12 in the region of the undercut portion 4k. Including the above-described case, the biting portion can be formed by making the thickness of the base material uniform and deforming it in the approaching direction to the skin.

During the above-described simultaneous vacuum suction, the cavity distance between the mold surface 16b and the mold surface 5b corresponds to the thickness of the skin 11 between the mold surface 16b and the thickness of the foam layer 12 of 4 mm with respect to the surface of the substrate 4. Even if it is set to have a gap of 5 mm on the general surface, the foam layer 12 is expanded or contracted according to these dimensional errors or non-similar shapes, and the gap is widened in the corner region having a small curvature radius. It is naturally expanded according to. On the other hand, as a further improvement plan, when a fine uneven wrinkle pattern having a maximum depth of about 0.1 mm is formed on the mold surface 16b so as to shape the surface of the skin material 10, a vacuum for the skin material is used. The gap between the suction mold surface 16b and the surface of the substrate 4 is set so that the thickness of the foamed layer before mold clamping is compressed to such an extent that faithful shaping is possible along with a fine mold surface change. . For example, it is preferable to set the gap size to be compressed at least about 20% when the mold is clamped with respect to a foam layer having a normal thickness of about 5 mm for automobile interior parts. For the foam layer 12 having a thickness of 4 mm of the above-mentioned material, it is confirmed that reliable transfer is performed by setting the gap size to be narrower than 5 mm so as to be compressed to about 3 to 2 mm in the entire wrinkle formation region. Has been. In addition, when the foamed layer 12 is compressed by about 50% to 2 mm as described above by such compression, the above-described compression wrinkle or crunching can be avoided without forming a biting portion.

  3 and 4 show another embodiment of the base material 4 with respect to the intake passage. For example, the base material 4 made of PP forms the intake passage 20 which is a concave groove communicating with each other on the surface in a mesh shape. It is injection-molded. In addition, a suction port 21 having a relatively large outer diameter is formed on the back side of the intersection of the mesh-shaped suction channel 20 in the center, and a single suction channel 22 is vacuum-sucked so as to communicate with this suction port. It is formed on the convex part 5a of the mold 5 and the main body. As shown in FIG. 4A, a square mesh-shaped intake passage 20 having a U-shaped cross section has a width A and a depth B set to about 1 to 0.5 mm, and mesh pitches C and D are 50 mm or more. It is preferable to set the following value, taking into consideration the shape of the interior product or the required adhesive strength.

  At the time of simultaneous vacuum suction after mold clamping, as shown in FIG. 4B, the mesh-like air intake passage 20 over the entire surface of the base material 4 is efficiently and intensively sucked from the suction port 21 in the central portion. Such a mesh-like arrangement makes it possible to suck substantially the entire area of the base material, the adhesion strength of the skin material can be easily improved, and the occurrence of swelling and the like after demolding can be reliably avoided. In addition, the suction port can be efficiently sucked to the entire area by forming it in the central part, but depending on the case, it may be provided other than the design part such as the back surface and the edge, or may be dispersed depending on the shape. It is also possible to form several.

The skin is PVC (polyvinyl chloride), the foam layer is PVC foam, the substrate is PC (polycarbonate) / ABS (acrylonitrile / butadiene / styrene terpolymer), or ASG (glass fiber reinforced acrylonitrile). A synthetic resin such as styrene can also be used, and a solvent evaporation type can also be used for adhesion to the substrate. In the case of a PP base material, it is also conceivable to apply an olefin-based adhesive.

It is a schematic sectional drawing of the vacuum forming machine explaining the vacuum forming process with respect to the base material of the skin material of the instrument panel by embodiment of this invention. It is a fragmentary sectional view of the instrument panel by the vacuum adhesion process. It is a schematic sectional drawing of the base material provided with the intake passage by another embodiment. FIG. 3 is a partial perspective view, and FIG. B is a view for explaining the operation. It is a figure explaining the formation process of the vacuum forming method of the skin material of the conventional instrument panel. It is a fragmentary sectional view of the instrument panel explaining the vacuum forming process by FIG. FIG. 1 shows an instrument panel to be vacuum bonded according to FIG. 1, in which FIG. A is a perspective view thereof, and FIG. B is a perspective view of a defroster thereof.

Explanation of symbols

4 Substrate 4c Substrate door portion 4d, 4e, 4g, 4h Encroaching part 5 Vacuum suction type for substrate
5a Convex type 5b, 16b Mold surface 7 Airbag door 8 Defroster 9 Instrument panel 10 Skin material 11 Skin 12 Foam layer 12b Undercut part 13 Olefin adhesive 16 Vacuum suction type for skin material 16a Concave 16c Concave 18 Clamp 19 Heater 20 Mesh air intake passage

Claims (7)

Set the injection-molded base material, which has a distributed air intake path and has a corner portion that bends in the direction intersecting the die-cutting direction , on the surface, and sets the skin material with foam layer on the surface of the base material In the vacuum forming method of the interior product for producing the interior product by adhering the skin material adsorbed on the base material by vacuum suction,
The vacuum suction mold for the base material is applied to one side of the upper and lower sides of the thermoplastic skin material supported in a flat shape, and the other corresponds to the surface shape of the entire skin to be shaped to the flat shape. for skin material vacuum mold having a mold surface is provided on the counter state to Rutotomoni, the shape of the mold surface of the vacuum suction type for the skin material, the gap to the skin material during the mold clamping compression of 20% to 50% Formed to be set between the surfaces of the substrate,
In a state where the skin material is softened by heating treatment, the vacuum suction mold for the base material and the vacuum suction mold for the skin material are clamped,
By vacuum suction from both sides in a clamped state with these vacuum suction molds, the foam layer is adhered to the base material, and the skin material is shaped along the mold surface of the vacuum suction mold for the skin material A vacuum forming method for interior parts, characterized by: On the mold surface of the vacuum suction mold for the skin material, the undercut portion is formed in the skin material without forming the shape to be compressed by 20% to 50% with respect to the demolding direction of the vacuum suction mold for the skin material. 2. A vacuum forming method for interior parts according to claim 1, wherein concave portions are formed in the intersecting direction.   The vacuum forming method for interior parts according to claim 1 or 2, wherein a hot-melt adhesive is laminated on the back surface of the foam layer. In the corner portion of the base material, there is formed a biting portion that cuts into the foam layer in a non-similar shape with respect to the corresponding corner portion of the vacuum suction mold surface for the skin material, and reduces its thickness The vacuum forming method for interior parts according to claim 1, claim 2, or claim 3. Intake path is distributed formed, and comprises a vacuum suction type to set the injection molded substrate having a corner portion that bends in the cross direction with respect to the die cutting direction to the surface, the base material by vacuum suction the foam layer with the surface material In the vacuum forming machine for interior parts to produce interior parts by adhering them while adsorbed on
A clamp device that clamps the periphery of a thermoplastic skin material supported in a flat shape and a heater that softens the clamped skin material by a heating process, and on one of both sides in the vertical direction with respect to the clamp device A vacuum suction mold for a substrate, and a vacuum suction mold for a skin material having a mold surface corresponding to the surface shape of the entire skin to be shaped with respect to the flat shape on the other side, is provided in an opposing state, and the skin material The shape of the vacuum suction mold surface is formed so that a gap for compressing the skin material by 20% to 50% can be set between the surfaces of the base material at the time of clamping,
The vacuum forming machine for interior parts, wherein the vacuum suction mold for the skin material and the vacuum suction mold for the base material are provided with suction means for performing vacuum suction simultaneously.   6. The vacuum molding machine for interior parts according to claim 5, wherein the surface of the vacuum suction mold for the skin material and the shape of the surface of the base material are partially formed to be non-similar to each other. Non-similar shape to the shape of the facing substrate surface so that the undercut part is formed in the skin material without forming the shape to be compressed 20% to 50% on the vacuum suction mold surface of the skin material A vacuum forming machine for interior parts according to claim 6, wherein a recess is formed in the interior.

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