JP2020029017A - Molded structure - Google Patents

Abstract

To suppress a situation where an end face of a base material is deformed.SOLUTION: A base material 30 containing fibers and thermoplastic resin has a plate-shaped part 33 having a plate shape, a rib 39 provided on a back surface 33A of the plate-shaped part 33, and a resin molded body 40 having an extended part 55 joined to an end surface 35A of the plate-shaped part 33. The rib 39 is disposed at a position adjacent to the end surface 35A on the back surface 33A. Thereby, a rigidity of the plate-shaped part 33 in the vicinity of the end surface 35A can be further increased. As a result, it is possible to suppress a situation in which the end surface 35A of the plate-shaped part 33 is deformed by a stress caused by a shrinkage when the resin molded body 40 is cooled and solidified during an injection molding.SELECTED DRAWING: Figure 3

Description

  The technology disclosed herein relates to a molded structure.

  2. Description of the Related Art Conventionally, there has been known a molded structure in which a resin molded body is integrally formed with a base material containing a fiber and a thermoplastic resin. Patent Literature 1 below describes a manufacturing method in which a resin molded body is molded by injecting a molten resin onto a substrate after molding the substrate with a pair of molding dies. The molten resin injected onto the substrate mixes with the thermoplastic resin constituting the substrate. As a result, the resin molded body is bonded to the base material.

Japanese Patent No. 5186883

  By the way, as a molded structure obtained by integrally molding the resin molded body with the base material, a configuration in which the resin molded body is joined to the end face of the base material can be considered. In the process of molding such a resin molded body, stress is generated at the end of the base material due to shrinkage when the resin molded body is cooled and solidified, and there is a concern that the end face of the base material may be deformed.

  The technology disclosed in this specification has been completed based on the above circumstances, and has an object to suppress a situation in which an end surface of a base material is deformed.

  As a means for solving the above problems, a molded structure disclosed in the present specification is a substrate containing fibers and a thermoplastic resin, and a plate-shaped plate-shaped portion, and one of the plate-shaped portions. A base provided with a rib provided on a surface of the plate-shaped portion, and a resin molded body having a joining portion joined to an end surface of the plate-shaped portion, wherein the rib is a portion adjacent to the end surface on the one surface. It is characterized by being arranged in.

  In the manufacturing process of the molded structure, for example, a base material (plate-shaped portion and rib) is formed by press-molding a plate-shaped member (pre-board) containing fibers and a thermoplastic resin, and thereafter, the plate-shaped member is formed by injection molding. The resin molded body can be molded in a form to be joined to the end face of the portion. The rib is disposed at a position adjacent to the end face. Thereby, the rigidity (second moment of area) in the vicinity of the end face in the plate-shaped portion can be further increased. As a result, it is possible to suppress a situation in which the end face of the plate-shaped portion is deformed by the stress caused by shrinkage when the resin molded body is cooled and solidified during injection molding.

  Further, the rib may extend along a direction intersecting with the end face. The second moment of area of the plate-shaped portion can be increased in a direction intersecting the end face of the plate-shaped portion. Accordingly, when the resin molded body is cooled and solidified, it is possible to suppress a situation in which the end surface of the plate-shaped portion is curved so as to protrude inside the plate-shaped portion.

  Further, the molded structure is a vehicle interior material, and the plate-shaped portion has a main wall portion having a main surface facing the vehicle interior side, and the main wall portion bent with respect to the main wall portion. And an upright wall portion rising from an end of the upright wall and constituting the end surface, wherein the rib extends from a portion of the upright wall portion adjacent to the end surface to the main wall portion. With such a configuration, it is possible to suppress a situation in which the standing wall portion is bent and deformed with respect to the main wall portion.

  ADVANTAGE OF THE INVENTION According to this invention, the situation which the end surface of a base material deforms can be suppressed.

1 is a perspective view of a pillar garnish according to an embodiment of the present invention, as viewed from a vehicle interior side. Perspective view of the pillar garnish viewed from outside the cabin Sectional view showing the pillar garnish (corresponding to the view cut along the line III-III in FIG. 2) Side view of pillar garnish viewed from the back Sectional view showing the molding device (the mold is open) Sectional view showing the press forming process Sectional view showing the injection molding step and the side wall of the pillar garnish (corresponding to the view cut along the line VII-VII in FIG. 4) The figure which shows typically the base material and resin molding of a comparative example The figure which shows typically the state which the end surface of the base material deformed with shrinkage of the resin molded object of the comparative example The figure which shows the modification of a rib. The figure which shows the modification of a rib. The figure which shows the modification of a rib. The figure which shows the modification of a rib.

<First embodiment>
Embodiment 1 of the present invention will be described with reference to FIGS. In the present embodiment, a pillar garnish 20 for a vehicle is exemplified as a molded structure. The pillar garnish 20 is a vehicle interior material (an example of a vehicle interior material) that is attached to a center pillar (B pillar, not shown) provided on a side wall of the vehicle interior from the vehicle interior side. As shown in FIG. 1, the pillar garnish 20 is provided on a main wall portion 24 that forms a main surface (a surface facing an occupant), and on both ends of the main wall portion 24 (both ends in the vehicle longitudinal direction). And a pair of side wall portions 25 and 26 provided.

  The main wall portion 24 has a vertically long plate shape, and an opening portion 24A for exposing a slide plate (not shown) to the vehicle interior side is formed in a central portion thereof. A pair of attachment pieces 27 and 28 attached to the center pillar are provided at a lower end 24 </ b> B of the main wall 24. As shown in FIG. 2, a clip seat 51 is formed on the rear surface of the upper end portion of the main wall portion 24 (the surface outside the vehicle compartment) so as to protrude outside the vehicle compartment. The clip seat 51 is configured to hold a clip (not shown), and the clip is attached to the center pillar. In addition, a plurality of reinforcing ribs 49 are formed on each back surface of the side wall portions 25 and 26 in a vertical direction. On the back surface of each of the side walls 25 and 26, an extending rib 50 extending along each side end of the side walls 25 and 26 is formed. The extension rib 50 is provided so as to connect a plurality of reinforcement ribs 49 arranged in the vertical direction.

  The pillar garnish 20 is composed of two parts having different materials. Specifically, as shown in FIG. 2, the pillar garnish 20 includes a substrate 30 which is a portion containing fibers and a thermoplastic resin, and a resin molded body 40 made of a thermoplastic resin. In FIG. 2, of the pillar garnish 20, the resin molded body 40 is illustrated by hatching, and a portion other than the hatching is the base material 30. The substrate 30 is formed by press molding, and the resin molded body 40 is formed by injection molding.

  As the fiber used for the substrate 30, for example, kenaf fiber is used, but the type of fiber is not limited to this. Wood fibers, glass fibers, carbon fibers, or the like may be used as the fibers used for the base material 30. In the substrate 30, the fibers are bound by a thermoplastic resin. The thermoplastic resin used for the substrate 30 can be exemplified by polypropylene, and the thermoplastic resin used for the resin molded body 40 can be exemplified by TSOP-5, but is not limited thereto. The thermoplastic resins used for the base material 30 and the resin molded body 40 may be different materials or may be the same material. Further, the shrinkage rate of the resin molded body 40 during molding is set to be larger than the shrinkage rate of the base material 30.

  The base material 30 includes a plate-shaped portion 33 having a plate-like shape, and a rib 39 (see FIG. 3, which will be described in detail later) provided on a back surface 33A (one surface of the plate-shaped portion) of the plate-shaped portion 33. The plate-like portion 33 includes a base-material-side main wall portion 34 that constitutes a major portion (a portion other than the upper end portion) of the main wall portion 24 and a major portion (a portion other than the upper end portion and the side end portion) of the side wall portion 25. It comprises a base material side wall portion 35 constituting the base material, and a base material side wall portion 36 constituting most of the side wall portion 26 (parts other than the upper end portion and the side end portion).

  As shown in FIG. 3, the base-material-side main wall portion 34 has a main surface 34 </ b> A facing the interior of the vehicle (the interior of the vehicle). The base material side wall portion 35 (standing wall portion) is configured to be bent from the base material side main wall portion 34 and rise from a vehicle front end portion (right side in FIG. 3) of the base material side main wall portion 34. . The base material side wall portion 36 (standing wall portion) is configured to be bent from the base material side main wall portion 34 and rise from the rear end of the vehicle of the base material side main wall portion 34.

  As shown by hatching in FIG. 2, the resin molded body 40 includes a plate-shaped plate portion 43, a clip seat 51, a reinforcing rib 49, and an extension rib 50. The plate-shaped portion 43 constitutes an end (an upper end and an end outside the vehicle compartment) of the pillar garnish 20 other than the lower end. Specifically, the plate-shaped portion 43 includes a resin molded body-side main wall portion 44 forming the upper end portion of the main wall portion 24, a resin molded body-side side wall portion 45 forming the upper end portion of the side wall portion 25, and a side wall portion 26. The resin molded body side wall portion 46 that forms the upper end portion, the extended portion 55 that forms most of the end portion of the side wall portion 25 outside the vehicle compartment, and the majority of the end portion of the side wall portion 26 that is outside the vehicle compartment. And an extending portion 56 to be configured. The extending portion 55 extends downward from the resin molded body side wall portion 45, and the extending portion 56 extends downward from the resin molded body side wall portion 46. The extending portion 55 (joining portion) extends along the end surface 35A of the base material side wall portion 35 and is joined to the end surface 35A, as shown in FIGS. Further, as shown in FIG. 1, the extending portion 56 (joining portion) extends along the end surface 36A of the base material side wall portion 36 and is joined to the end surface 36A.

  As shown in FIGS. 3 and 4, ribs 39 are integrally provided on the back surface 33 </ b> A of the plate-shaped portion 33 (the back surface of the base material side wall portion 35 and the back surface of the base material side wall portion 36). The rib 39 formed on the base material side wall portion 35 is disposed at a position adjacent to the end surface 35A on the back surface 33A, and the rib 39 formed on the base material side wall portion 36 is adjacent to the end surface 36A on the back surface 33A. It is arranged in the place to be. As shown in FIG. 4, a plurality of ribs 39 formed on the base material side wall portion 35 are provided in a line along the extending direction of the extending portion 55. Although not shown, a plurality of ribs 39 formed on the base material side wall portion 36 are arranged in a line along the extending direction of the extending portion 56. In FIG. 4, the members included in the base material 30 are indicated by solid lines, and the members included in the resin molded body 40 are indicated by two-dot chain lines. Note that "the rib 39 is disposed at a position adjacent to the end face 35A" means that the rib 39 is provided at least on the base material side wall 35 (standing wall). Further, as shown in FIG. 4, it is more preferable that the rib 39 is disposed on the end 35 </ b> B of the base material side wall 35.

  Further, each rib 39 is arranged at the same position in the vertical direction (in the horizontal direction in FIG. 4) as each reinforcing rib 49, and as shown in FIG. 3, the reinforcing rib 49 and the rib 39 are joined to each other. It is formed integrally. As shown in FIG. 4, the ribs 39 formed on the base material side wall portion 35 extend along a direction intersecting (substantially orthogonal) with the end surface 35A (vertical direction in FIG. 4). As shown in FIG. 3, the rib 39 formed on the base material side wall portion 35 extends from a portion of the base material side wall portion 35 adjacent to the end surface 35A to the base material side main wall portion 34. The rib 39 formed on the base material side wall portion 36 extends from a portion of the base material side wall portion 36 adjacent to the end surface 36A to the base material side main wall portion 34.

  Next, a molding device 60 for molding the pillar garnish 20 of the present embodiment will be described. In the present embodiment, a description will be given by exemplifying a portion of the molding device 60 where the side wall portion 25 of the pillar garnish 20 is molded. As shown in FIG. 7, the molding device 60 includes a molding die 61 and an injection device (not shown). The mold 61 includes a core mold 62 and a mold mold 63 (a pair of molds) which are arranged to face each other. The core mold 62 and the mold mold 63 can be moved toward or away from each other by a drive device (not shown) (for example, an electric motor, an air cylinder, a hydraulic cylinder, or the like). Thus, the core mold 62 and the mold mold 63 can be closed and opened. The molding surface 62A of the core mold 62 is a molding surface for mainly molding the back surface (the surface outside the vehicle compartment) of the pillar garnish 20, and the molding surface 63A of the mold cavity 63 is a molding surface of the pillar garnish 20 (the vehicle interior). (The inner surface).

  In the mold closed state shown in FIG. 7, a molding space S1 for molding the resin molded body 40 (in FIG. 7, the resin molded body side wall 45 of the plate-shaped portion 43 is shown) is formed between the core mold 62 and the mold cavity 63. It is formed. A groove 64 (a part of the molding space S1) for molding the rib 39 and the reinforcing rib 49 is formed on the molding surface 62A of the core mold 62. An injection device (not shown) is attached to the core mold 62, and the molten resin supplied from the injection device is injected into the molding space S1 and the groove 64. The forming die 61 includes slide dies (not shown) for forming the undercut portions of the extension rib 50, the clip seat 51, and the extension portions 55 and 56.

  The method for manufacturing the pillar garnish 20 according to the present embodiment includes a press forming step in which the plate-shaped member 70 containing fibers and a thermoplastic resin is press-formed by the core mold 62 and the mold mold 63 to form the base material 30; An injection molding step of molding the resin molded body 40 in such a manner as to be joined to the base material 30 by injecting the molten resin. Note that the plate member 70 may be called a preboard.

  In the press forming step, the plate member 70 which has been softened by heating in advance is disposed between the core mold 62 and the mold mold 63 as shown in FIG. Subsequently, as shown in FIG. 6, the plate member 70 is press-formed by closing the core mold 62 and the mold mold 63. Thereby, the plate-like member 70 has a shape following the shape of the molding surfaces 62A and 63A, and becomes the base material 30. When the plate-like member 70 is press-formed, the portion of the plate-like member 70 facing the groove 64 is not compressed, but rises relatively to the surroundings, thereby forming the rib 39. In addition, the thickness of the plate-shaped portion 33 of the base material 30 is set to, for example, 2 mm, and the protrusion height of the rib 39 is set to 1.7 mm, but each dimension is not limited to these values.

  In the injection molding process performed after the press molding process, a molten resin (for example, polypropylene or the like) is injected into the molding space S1 (including each groove 64) in a state where the base material 30 is sandwiched by the core mold 62 and the mold mold 63. I do. In the process of filling the molding space S1 with the molten resin, the molten resin permeates into the fibers of the base material 30 at the contact points with the base material 30. At the same time, the molten resin that has permeated into the fibers mixes with the softened thermoplastic resin inside the base material 30 and becomes completely integrated (blended and melted).

  Thereafter, by cooling and solidifying the molten resin, the molten resin filled in the molding space S1 becomes a resin molded body 40 joined to the base material 30. For example, the extending portion 55 is formed in a state of being joined to the end surface 35A of the base material side wall portion 35, and the extending portion 56 is in a state of being joined to the end surface 36A of the base material side wall portion 36. Molded. Further, the molten resin filled in the groove portion 64 in the molding space S1 becomes the reinforcing rib 49 joined to the rib 39. By thus integrally forming the base material 30 and the resin molded body 40, the pillar garnish 20 is completed.

  Next, effects of the present embodiment will be described. In the manufacturing process of the pillar garnish 20, the base material 30 (including the plate-shaped portion 33 and the rib 39) is formed by press-forming the plate-shaped member 70 (pre-board) containing the fiber and the thermoplastic resin as described above, After that, the resin molded body 40 can be molded by joining with the end surface of the plate-shaped portion 33 by injection molding. The rib 39 is disposed at a position adjacent to the end surfaces 35A and 36A of the plate-shaped portion 33. Thereby, the rigidity (second moment of area) in the vicinity of the end surfaces 35A and 36A in the plate-shaped portion 33 can be further increased. As a result, it is possible to suppress a situation in which the end surfaces 35A and 36A of the plate-shaped portion 33 are deformed due to stress caused by shrinkage when the resin molded body 40 is cooled and solidified during injection molding.

  As shown in the comparative example of FIG. 8, the resin molded body 4 (corresponding to the extended portions 55 and 56 of the present embodiment) is joined to the end surface 3A of the base material 3 (corresponding to the end surfaces 35A and 36A of the present embodiment). When molded in a shape, the base material 3 and the resin molded body 4 contract when cooled and solidified. In general, the resin molded body 4 has a large shrinkage ratio with respect to the base material 3 containing fibers. For this reason, when the resin molded body 4 contracts, a stress acts on the base material 3 joined at the end face 3A which is the joining face, and as shown in FIG. There is a concern about the state of being curved in such a manner as to protrude inward. When the end face 3A is deformed, for example, a gap is formed in a parting-off portion with another member, and there is a concern that a design may be deteriorated. In the present embodiment, the rib 39 is provided near the end surface (35A, 36A) of the base material 30 and the rigidity is increased, so that such a situation can be suppressed.

  The rib 39 extends along a direction intersecting the end surface 35A. The secondary moment of area of the base material side wall portion 35 can be increased in a direction intersecting the end surface 35A of the base material side wall portion 35 (plate-like portion 33). Accordingly, when the resin molded body 40 is cooled and solidified, it is possible to suppress a situation in which the end surface 35A of the plate-shaped portion 33 is curved so as to protrude inside the plate-shaped portion 33.

  In addition, the plate-shaped portion 33 has a main surface 34A having a main surface 34A facing the interior of the vehicle cabin, and an end of the main wall 34 that is bent with respect to the main wall 34. The rib 39 extends from a position adjacent to the end surface 35A in the base material side wall portion 35 to the base material side main wall portion 34. Thereby, the situation where the base material side wall portion 35 is bent and deformed with respect to the base material side main wall portion 34 can be suppressed.

  In the present embodiment, the terminal portion of the pillar garnish 20 is formed of the resin molded body 40. During press molding, burrs may be formed on the end face of the substrate 30. Therefore, if the terminal portion of the pillar garnish 20 is formed of the base material 30, it is necessary to perform terminal processing. In the present embodiment, since the terminal portion of the pillar garnish 20 is formed of the resin molded body 40, it is preferable that no burr occurs. Further, it is difficult to form the undercut portion (the seat surface portion of the clip seat 51, the reinforcing rib 49, and the like) by press molding, so that it is difficult to form the undercut portion with the base material 30. In this regard, in the case of the resin molded body 40, the undercut portion can be formed by injection molding using a slide mold or the like.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and the drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the above embodiment, the pillar garnish was illustrated as the molded structure, but is not limited thereto. The molded structure may be a vehicle interior material such as a board member (upper board or the like) constituting a door trim, an instrument panel, a luggage trim, a package tray, or the like. Further, the molded structure may be an interior material (vehicle interior material) mounted on a vehicle other than a vehicle, or may be a member other than the interior material.
(2) The shape of the rib formed on the plate-shaped portion 33 of the base material 30 is not limited to the shape exemplified in the above embodiment. For example, as shown in FIG. 10, a rib 139 may be provided to connect a plurality of ribs 39, or as shown in FIG. 11, a rib 239 extending along the end surface 35A may be provided. . In addition, a plurality of X-shaped ribs 339 may be provided as shown in FIG. 12, or a plurality of U-shaped ribs 439 may be provided as shown in FIG.

Reference numeral 20: pillar garnish, 30: base material, 33: plate-like portion, 33A: back surface of the plate-like portion (one surface of the plate-like portion), 34A: main surface, 34: base-material-side main wall portion (main wall portion) ), 35: base material side wall portion (standing wall portion), 35A: end face of plate-shaped portion, 39, 139, 239, 339, 439 ... rib, 40 ... resin molded body, 55, 56 ... extension portion (joining portion) )

Claims (3)

A substrate including fibers and a thermoplastic resin, a plate-shaped plate-shaped portion, and a substrate provided with a rib provided on one surface of the plate-shaped portion,
A resin molded body having a joining portion to be joined to the end face of the plate-shaped portion,
A molded structure in which the rib is disposed at a position adjacent to the end surface on the one surface.   The molded structure according to claim 1, wherein the rib extends along a direction intersecting the end face. The molded structure is a vehicle interior material,
The plate-shaped portion has a main wall portion having a main surface facing the interior of the vehicle, and a standing wall portion rising from an end portion of the main wall portion and forming the end surface in a form bent with respect to the main wall portion, With
The molded structure according to claim 1, wherein the rib extends from a portion of the upright wall portion adjacent to the end face to the main wall portion. 4.

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