JP2006096304A - Interior part for car - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an interior part for a car partly including a laminate structure which is capable of reducing the weight of a product, and enhancing the formability and releasability of an undercut part. <P>SOLUTION: A door trim 10 comprises a laminate structure (a door trim upper) 20 in which a resin-made rib 22 is integrally laminated to a back side of a lightweight foaming resin base material 21 with the shape keeping property and a decorative material 23 is affixed to a face side thereof, and a resin single article (a door trim lower) 30. The decorative material 23 is constituted of the laminate structure of at least two layers, i.e., a top layer 23a and a cushion layer 23b. By adequately setting the elasticity and the thickness of the cushion layer 23b, the door trim upper 20 is easily released from an undercut-shaped projecting part 418 of a forming mold 40. The releasing workability is enhanced, the forming mold 40 is simplified, and the drawing pattern is transferred with excellent accuracy. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to interior parts for automobiles such as door trims, rear parcel shelves, floor trims, trunk trims, rear side trims, pillar garnishes, roof trims, and the like, particularly for automobiles that are lightweight and have excellent exterior design and formability. For interior parts.

  For example, the configuration of automobile interior parts will be described with reference to FIGS. The door trim 1 has shape retention and attachment rigidity to a vehicle body panel, and is configured by laminating and integrating a skin 3 excellent in surface appearance on the surface of a resin core material 2 extending over almost the entire product surface. . Reference numeral 2a denotes an inner seal mounting flange for mounting the inner seal. The resin core material 2 is made of polypropylene resin mixed with talc, and the skin 3 itself does not have shape retention, such as a vinyl chloride sheet, a thermoplastic olefin (hereinafter referred to as TPO) sheet, or the like. The synthetic resin sheet is usually used.

  Next, a conventional example of the method for forming the door trim 1 will be described with reference to FIG. First, a molding die 4 for molding the door trim 1 is connected to a molding upper die 4a that can move up and down by a predetermined stroke, a molding lower die 4b that is paired with the molding upper die 4a, and a molding lower die 4b. It is generally composed of the injection machine 4c. Then, after the upper and lower molds 4a and 4b are clamped, in order to shape the product shape of the door trim 1, a cavity part 4d is formed in the molding upper mold 4a, and a core part 4e is provided in the molding lower mold 4b. Yes.

  In order to drive the molding upper die 4a up and down by a predetermined stroke, an elevating cylinder 4f is connected, and the molding lower die 4b is provided with a manifold 4g and a valve gate 4h serving as a passage for a molten resin from the injection machine 4c. . In addition, in order to have an appropriate posture, the molding upper die 4a that moves up and down has guide posts 4i erected at the four corners of the molding lower die 4b, and guide bushes 4j are provided corresponding to the guide posts 4i. It has been.

  Therefore, when the molding upper and lower molds 4a and 4b are in the mold open state, the skin 3 is set in the mold, and after that, the molding upper and lower molds 4a and 4b are clamped and then injected into the cavity between the molds. By injecting and filling the molten resin M from 4c through the manifold 4g and the valve gate 4h, the resin core material 2 is formed into a required curved shape, and the skin 3 is integrally formed on the surface of the resin core material 2 (for example, , See Patent Document 1). In FIG. 12, for convenience of explanation, the molten resin M is supplied to the mold surface of the core portion 4e in an open state, but the molten resin M is injected and filled into the cavity after the upper and lower molds 4a and 4b are clamped. May be.

  However, in the door trim 1 and the molding method described above, the projected area of the resin core material 2 is large, and thus there are problems that the material cost is high and the product is heavy. In addition, since the projected area of the resin core material 2 is large, it is necessary to set the injection pressure at the time of molding high, and a mold structure that can withstand the high injection pressure is required. In addition, since it is necessary to cool and solidify a large amount of molten resin, the molding cycle is prolonged, which is a major factor for reducing productivity.

  Recently, a door trim 1 shown in FIGS. 13 and 14 has been proposed in order to solve the above-described problems and achieve a reduction in weight of a product and reduce a load during molding. The door trim 1 includes a door trim upper 1a made of a laminated structure and a door trim lower 1b made of a single synthetic resin. In particular, in order to promote weight reduction, the door trim upper 1a has the following structure: A lightweight and rigid foamed resin base material 5 is used, and a lattice-shaped reinforcing rib 6 is disposed on the back surface of the foamed resin base material 5 at a portion where further rigidity is required. The epidermis 7 is affixed (for example, refer patent document 2).

  And the shaping | molding method which shape | molds the door trim upper 1a mentioned above is demonstrated. First, as shown in FIG. 15, a molding die 4 used in this molding method is composed of a molding upper mold 4a, a molding lower mold 4b, and an injection machine 4c. The molding upper mold 4a includes a cavity portion 4d. Is set, and the core 4e is provided in the molded lower mold 4b.

  The upper molding die 4a is connected to the elevating cylinder 4f and can move up and down by a predetermined stroke, and the lower molding die 4b is provided with a manifold 4g and a valve gate 4h. In this molding die 4, a vacuum mechanism 8 is provided to accurately mold the skin 7 into a product shape and to squeeze and transfer it onto the product surface of the skin 7. In addition, in order to form an undercut portion A such as a pull handle attachment recess in the door trim upper 1a, an undercut insert 9 and a drive cylinder 9a are set in the molding upper die 4a. Therefore, in order to mold the door trim upper 1a, the raw sheet of the foamed resin base material 5 is heat-softened and then put into the mold, and the skin 7 is set in advance on one side of the original sheet, and then molded. While the foamed resin base material 5 is molded into a required shape by clamping the upper and lower molds 4a and 4b, the skin 7 is integrally attached to the surface side thereof.

  At this time, the skin 7 is molded into a product surface shape by the vacuum mechanism 8 of the molding upper die 4a, and desired drawing transfer is performed. Further, the drive cylinder 9a is in an extended state at the time of molding, and the undercut insert 9 enters the cavity to form an undercut portion A. After the forming, the drive cylinder 9a performs a contracting operation, and the undercut insert is inserted. By retreating 9, the undercut portion A of the molded product (door trim upper) 1a can be easily removed. After the mold upper and lower molds 4a and 4b are clamped, molten resin is filled from the injection machine 4c into the groove 4k through the manifold 4g and the valve gate 4h, and the reinforcing rib 6 is molded.

JP 10-138268 A

Japanese Patent No. 3476083

  As described above, when the foamed resin base material 5 that is light in weight and has an appropriate shape retaining property is employed instead of the conventional resin core material 2, an undercut portion A is formed, so that the undercut driven by the drive cylinder 9 a is used. Since the cutting insert 9 is used, there is a drawback that the structure of the molding die 4 is complicated and the die equipment is soared. Further, as shown in the enlarged view in FIG. 15, the molded door trim upper 1a has a nesting line a conspicuous on the surface of the product, resulting in a decrease in appearance performance, and a portion where the undercut nesting 9 is set has a vacuum suction force. Cannot be applied to the entire surface of the product, and this also causes a decrease in appearance performance.

  The present invention has been made in view of such circumstances, and the entire laminated structure in which a decorative material is pasted on the surface of a foamed resin base material that is lightweight and has an appropriate shape retaining property instead of a resin core material. To provide an automotive interior part that is adopted as a part, and that can transfer a drawing pattern even in an undercut portion and that can simplify the structure of a molding die. Objective.

  As a result of earnest research, the present inventors have given the function as a core material by imparting shape retention to the foamed resin sheet that has been used conventionally as the skin, and more. In places where rigidity is required, that is, peripheral parts and panels of products, parts mounting places and parts where loads are applied, resin ribs with excellent rigidity are arranged, and other parts are made into a hollow shape, Compared to conventional resin core materials with a large projected area, it provides interior trim parts that are lighter and less expensive, and in particular, a decorative material with excellent cushioning properties is laminated on the surface of the foamed resin base material to soften the product. While giving a feeling, it paid attention to the elastic action of a decorating material, and came to complete this invention by utilizing this elastic action at the time of mold release from a shaping die.

  That is, the automobile interior part according to the present invention has a predetermined pattern shape that is molded into a required shape, is lightweight and has shape retention, and is laminated and integrated on the back surface of the foam resin substrate. In an interior part for an automobile in which a laminated structure composed of a resin rib and a decorative material affixed to the surface of the foamed resin substrate is employed in whole or in part, the decorative material in the laminated structure is: A foamed resin sheet composed of a laminated structure of at least two layers, a top layer and a cushion layer, and a heat-softened foamed resin sheet and a decorating material are put into a molding die, and the foaming resin is clamped by the molding die. The undercut part is formed by the undercut-shaped convex part provided on the molding die on one side and molded into a required shape in a state where the decorative material is laminated and integrated on the surface of the base material, and the above Underka Than undercut amount of isolation portion by setting the thickness of the cushion layer in the decorative material thick, characterized in that to allow demolding operation the undercut portion of the laminated structure.

  Here, as an interior part for an automobile, as long as it has a structure including at least a part of a laminated structure, for example, a door trim, a rear parcel shelf, a floor trim, a luggage trim, a trunk trim, a rear side trim, Applicable to pillar garnish, roof trim, etc.

  Furthermore, the laminated structure is molded into a desired curved shape, is lightweight and has a shape-retaining foamed resin base material, and a resin rib having a predetermined pattern shape laminated and integrated on the back surface of the foamed resin base material. The foamed resin base material is formed into a required curved shape in the molding die after heat-softening the foamed resin sheet. The shape is retained by molding. The term “shape retention” as used herein refers to having sufficient rigidity to retain the shape at least when the mold is removed after molding, even without a reinforcing material such as a rib.

  As the foamed resin sheet, a material obtained by adding a foaming agent to a thermoplastic resin is used. The thermoplastic resin may be one type of thermoplastic resin or two or more types of thermoplastic resins. Preferably, polyethylene resin, polypropylene resin, polystyrene resin, polyacetal resin, polyethylene terephthalate resin, polyvinyl alcohol resin, polyamide resin, vinyl chloride resin, ionomer resin, acrylonitrile / butadiene / styrene (ABS) Resin, polycarbonate resin and the like can be used. As the foaming agent, an azo compound such as azodicarbonamide, an organic foaming agent such as a sulfohydrazide compound, a nitroso compound or an azide compound, or an inorganic foaming agent such as sodium bicarbonate can be used. The foamed resin base material obtained by molding the foamed resin sheet into a required shape after heat softening treatment preferably has a foaming ratio of 2 to 10 times in consideration of the balance between the weight and strength of the product. The cell diameter of the foamed resin base material at that time is preferably in the range of 0.1 μm to 2.0 mm, and the thickness is 0.5 to 30 mm, preferably 1 to 10 mm.

  On the other hand, the thermoplastic resin material used as the resin rib can be appropriately selected from a wide range of thermoplastic resins. Usually, those that can be preferably used include polyethylene resins, polypropylene resins, polystyrene resins, polyacetal resins, polyethylene terephthalate resins, polyvinyl alcohol resins, polyamide resins, vinyl chloride resins, ionomer resins, acrylonitrile / butadiene / Styrene (ABS) resin, polycarbonate resin and the like can be used. Moreover, you may mix various fillers in these thermoplastic resins. Examples of the filler that can be used include inorganic fibers such as glass fiber and carbon fiber, and inorganic particles such as talc, clay, silica, and calcium carbonate. Moreover, various additives, such as antioxidant, a ultraviolet absorber, a coloring agent, a flame retardant, and a low shrinkage agent, may be mix | blended.

  And as a decorating material laminated and integrated on the surface of the foamed resin base material in order to enhance the appearance design, a laminated structure composed of at least a top layer and a cushion layer is used. As the top layer, a thermoplastic resin sheet such as thermoplastic urethane (hereinafter referred to as TPU), TPO, or polyvinyl chloride (hereinafter referred to as PVC) can be used. On the other hand, as the cushion layer, a foamed resin sheet such as polyurethane foam, polyethylene foam, and polypropylene foam can be used. In addition, a back surface nonwoven fabric layer, for example, a polyethylene fiber nonwoven fabric, a polypropylene fiber nonwoven fabric, a blended nonwoven fabric in which a polyester fiber and a polypropylene fiber are mixed can be used on the back surface of the cushion layer. At this time, the elasticity of the cushion layer is preferably in the range of Shore hardness C10 to 60 for urethane worm, and Shore hardness C40 to 90 for polyethylene foam, and the thickness is preferably set to 1 to 10 mm.

  Next, for the method of integrating the foamed resin sheet and the decorating material, first, the molding die to be used is composed of a pair of split molds and an injection machine attached to the mold on one side. Yes. For example, it is comprised from the shaping | molding upper die which can be moved up and down, the shaping | molding lower die which is a fixed side located in the downward side of a shaping | molding upper die, and the injection machine connected with a shaping | molding lower die. When the molding upper and lower molds are used, the molten resin supplied from the injection machine passes through resin passages such as a manifold and a gate provided in the molding lower mold, that is, on the mold surface of the molding lower mold, that is, the mold of the molding lower mold. The molten resin is injected and filled into a groove portion (corresponding to a resin rib shape) formed in the surface.

  Furthermore, a vacuum suction mechanism is attached to the molding upper die facing the decorating material, and an undercut convex portion is formed. The convex dimension of this undercut convex part is set smaller than the thickness of the cushion layer in a decorating material. In addition, the foamed resin base material and the decorative material are integrally press-molded by this molding die, but the foamed resin sheet, which is the material of the foamed resin base material, is heated and softened to a predetermined temperature by the heater device, and the mold is opened. It is put into the molding die. At this time, the foamed resin sheet and the decorating material may be laminated in advance, or individual raw sheets may be put into the molding die.

  And according to the interior parts for automobiles concerning the present invention, as a structure of a laminated structure, a lightweight foamed resin base material, a hollow resin rib disposed on the back side thereof, and a foamed resin base material surface Therefore, weight reduction can be achieved by eliminating the conventional heavy resin core material.

  Furthermore, at the time of molding the laminated structure, the decorating material is molded along the mold surface shape of the molding die, and the undercut part is integrally molded, but the decorating material is more than the undercut amount of the undercut part. Since the thickness of the cushion layer is set to be thick, the undercut portion can be easily removed from the mold by the elastic action of the cushion layer. At this time, even the foamed resin base material can be expected to have a slight elastic action, and therefore the undercut portion can be more easily removed from the mold by the synergistic effect of both.

  Therefore, by eliminating the nesting, the conventional nesting wire is not conspicuous to the outside, and the drawing pattern can be transferred to the entire surface of the product, and the undercut nesting and the drive cylinder are also abolished for the mold structure. be able to.

  As described above, the automotive interior component according to the present invention is a lightweight and shape-retaining foamed resin base material, a resin rib laminated and integrated on the back surface of the foamed resin base material, and a foamed resin base material. The entire structure, or at least a part, is composed of a laminated structure composed of decorative materials affixed to the surface of the material, so the conventional heavy resin core material can be eliminated, making it lightweight and low cost It is possible to provide interior parts for automobiles.

  Furthermore, in the automotive interior component according to the present invention, when the undercut portion is integrally formed in the laminated structure, the slide-type undercut insert that drives the cylinder is abolished, and the undercut-shaped convex portion is provided in the mold. The mold structure can be simplified, and the drawing pattern can be transferred to the entire surface of the product including the undercut part, so that the nesting lines do not stand out and the appearance performance is improved. In addition, there is an effect that the demolding operation of the laminated structure can be performed smoothly.

  Hereinafter, a preferred embodiment of an automobile interior part according to the present invention will be described by illustrating an automobile door trim.

  FIG. 1 to FIG. 9 show an embodiment of the present invention. FIG. 1 is a front view showing a two-tone type automobile door trim, FIG. 2 is a cross-sectional view showing the configuration of the automobile door trim, and FIG. 4 is a front view showing a resin rib and a door trim lower of the door trim upper in the door trim, FIG. 4 is a cross-sectional view showing a main configuration of the door trim upper in the automobile door trim, and FIG. FIG. 6 to FIG. 9 are explanatory views showing respective steps of a method for forming a door trim upper in the automobile door trim.

  1 and 2, a two-tone type automobile door trim 10 is composed of an upper and lower divided body of a door trim upper 20 made of a laminated structure and a door trim lower 30 made of a single resin product. As functional components to be mounted on the door trim 10, an inside handle escutcheon 11, a power window switch escutcheon 12, and a pull handle 13 are attached to the door trim upper 20. On the other hand, the door trim lower 30 is provided with a door pocket opening 14, and a pocket back cover (made of a resin molding) 15 is attached to the rear side of the door trim lower 30, as shown in FIG. A speaker grill 16 is formed integrally or separately on the front side. Note that reference numeral 17 in FIG. 2 denotes a door inner panel.

  By the way, the door trim 10 for automobiles according to the present invention is characterized in that the door trim upper 20 which is a laminated structure is reduced in weight, and the appearance performance and touch feeling of the door trim upper 20 are improved. That is, as shown in FIG. 2, the door trim upper 20 is molded into a desired curved surface shape and has a foamed resin base material 21 having shape retention, and a reinforcement integrated and laminated on the back surface side of the foamed resin base material 21. The resin rib 22 having a function and a decorating material 23 having a decorating function laminated and integrated on the surface side of the foamed resin base material 21 are roughly constituted. In addition, the foamed resin base material 21 is heat-softened to heat the foamed resin sheet so as to have shape retention, and then thermoformed into a required shape, for example, cold press-molded with a molding die having a desired mold surface.

  The foamed resin sheet has a configuration in which a foaming agent is added to a general-purpose thermoplastic resin. The thermoplastic resin includes a polyethylene resin, a polypropylene resin, a polystyrene resin, a polyacetal resin, a polyethylene terephthalate resin, a polyvinyl alcohol. Resin, polyamide resin, vinyl chloride resin, ionomer resin, acrylonitrile / butadiene / styrene (ABS) resin, polycarbonate resin, etc. can be used, and foaming agents include organic foaming agents such as azodicarbonamide and bicarbonate An inorganic foaming agent such as sodium can be used. In this embodiment, a foamed resin sheet in which sodium bicarbonate is appropriately added as a foaming agent to a polypropylene resin is used. The expansion ratio of the foamed resin base material 21 is set to 2 to 10 times, and the thickness is set to a range of 0.5 to 30 mm, particularly 1 to 10 mm.

  Next, the resin ribs 22 are disposed on the back surface side of the foamed resin base material 21 and, in particular, as shown in FIG. 3, are set in a predetermined pattern extending in an intersecting manner, and a portion to which a load is applied (for example, a clip seat). The portion excluding the upper surface of the waist portion, the upper surface of the armrest portion, etc.) has a thinned shape. In addition, as for this pattern, arbitrary patterns may be selected as long as it is intersecting, such as a vertical and horizontal direction, an oblique direction, or a combination thereof. The resin rib 22 is made of a general-purpose synthetic resin molded body, and a polyethylene resin, a polypropylene resin, a polystyrene resin, a polyacetal resin, a polyethylene terephthalate resin, a polyvinyl alcohol resin, a polyamide as a synthetic resin that can be preferably used normally. Resin, vinyl chloride resin, ionomer resin, acrylonitrile / butadiene / styrene (ABS) resin, polycarbonate resin, etc., and in this embodiment, polypropylene resin in consideration of environmental and recycling aspects. Is used. The resin rib 22 is appropriately mixed with a filler such as inorganic fibers such as glass fiber and carbon fiber, and inorganic particles such as talc, clay, silica and calcium carbonate in the thermoplastic resin. May be.

  As described above, the door trim 10 shown in FIGS. 1 to 3 includes the door trim upper 20 formed of a laminated structure and the door trim lower 30 of a single resin, and has an excellent appearance design due to an accent effect on the appearance. I have. Further, as shown in FIG. 4, the door trim upper 20 has a foamed resin base material 21 having shape retention, a resin rib 22 laminated and integrated on the back surface of the foamed resin base material 21, and a decorative decoration. Since it is comprised from the material 23, since the resin core material occupied over the whole product like the former can be abolished, and the lightweight foamed resin base material 21 is used, about the weight of a product conventionally The weight can be reduced compared to the example, the resin material can be saved, and the cost can be reduced. Furthermore, since the foamed resin base material 21 has a porous structure, the door trim upper 20 is excellent in sound absorption performance, can absorb noise entering the vehicle interior from the outside of the vehicle, and can reduce noise in the vehicle interior.

  Moreover, the decorating material 23 affixed on the surface of the foamed resin base material 21 is comprised from the laminated structure of at least 2 layer of the top layer 23a and the cushion layer 23b laminated | stacked and integrated on the back surface. In this embodiment, a TPO sheet is used as the top layer 23a, but a synthetic resin sheet such as TPU or PVC can be used. Furthermore, as the cushion layer 23b, a cushion sheet having a desired thickness such as polyurethane foam or polyethylene foam is used. The thickness of the top layer 23a is preferably set to 0.05 to 5 mm, and the thickness of the cushion layer 23b is preferably set to 1.5 to 10 mm. In particular, as the physical properties of the cushion layer 23b, for example, polyurethane foam is used. When the material is used, it is preferable to have elasticity having a Shore hardness C of 10 to 60. When polyethylene foam is used as the material, the material having the Shore hardness C of 40 to 90 is also preferable. As will be described later, a drawing pattern engraved on the mold surface of the molding die is beautifully transferred over the entire surface of the product of the decorating material 23. This portion is the undercut portion A in the mold opening direction of the mold for molding the door trim upper 20), and the drawn pattern does not flow, and the drawn pattern is beautifully transferred.

  Moreover, as an undercut amount of the undercut portion A (indicated by d in FIG. 4), when polyurethane foam is used as the cushion layer 23b, the shore hardness C of the polyurethane foam is 10 to 60, and the plate thickness is 3 mm. If it is a case, it is possible to set the undercut amount to a maximum of 2.5 mm. When a polyethylene foam is used as the cushion layer 23b, the Shore hardness C is 40 to 90, and the plate thickness is 3 mm. In this case, it is possible to set the undercut amount to 2 mm at the maximum. Thus, it is a necessary condition to set the plate thickness d1 of the cushion layer 23b to be thicker than the undercut amount d of the undercut portion A.

  For reference, the joint structure between the door trim upper 20 and the door trim lower 30 is provided with a mounting boss projecting on one side and a mounting hole on the other side at the joint edge of the door trim upper 20 and the door trim lower 30. After the installation and insertion of the mounting boss into the mounting hole, the door trim upper 20 and the door trim lower 30 are firmly joined by fixing the tip with ultrasonic welding caulking, heat welding caulking or the like.

  Next, the configuration of the molding die 40 used in the molding method of the door trim upper 20 will be described with reference to FIG. The molding die 40 that molds the door trim upper 20 includes a molding upper mold 41 that can move up and down by a predetermined stroke, a molding lower mold 42 that is paired with the molding upper mold 41, and an injection that is connected to the molding lower mold 42. The machine 43 is generally configured. More specifically, the molding upper die 41 is formed with a cavity portion 411 that matches the product shape, and the molding upper die 41 is driven up and down by a predetermined stroke by an elevating cylinder 412 connected to the upper surface of the molding upper die 41. . The upper mold 41 is provided with a vacuum mechanism. That is, a vacuum chamber 413 is provided in the molding upper die 41, and a large number of vacuum suction holes 414 are formed on the mold surface of the molding upper die 41 so that the vacuum chamber 413 and the cavity portion 411 communicate with each other. The vacuum chamber 413 is connected to a vacuum pump 416 via a vacuum suction pipe 415, and the vacuum suction pipe 415 is provided with an open / close valve 417. The molding upper die 41 is provided with an undercut-shaped convex portion 418 so as to form an undercut portion A provided in the door trim upper 20 and accommodates the edge of the pull handle 13 of the door trim upper 20. The stepped portion corresponds to this, and the undercut amount d is set to about 2 mm. On the other hand, the molding lower mold 42 is provided with a core part 421 so as to form a product-shaped cavity facing the cavity part 411 of the molding upper mold 41, and the molten resin M formed from the injection machine 43 is The ribs 424 are formed in the core portion 421 through the hot runner 422 and the valve gate 423 for injection filling.

  Then, a method for forming the door trim upper 20 using the molding die 40 will be described with reference to FIGS. First, in FIG. 6, the molding die 40 is in the upper position, and the molding die 40 is in an open state. At this time, the decorating material 23 is laminated on the foamed resin sheet S, which is the material of the foamed resin base material 21, and the laminate material of the foamed resin sheet S and the decorating material 23 is heated and softened by a heater device (not shown). After that, it is put into the molding die 40. In this embodiment, a TPO sheet (thickness 0.5 mm) of the top layer 23a, a polyurethane foam of the cushion layer 23b, a shore hardness C of 40, and a thickness of 3 mm are used as the decorating material 23.

Then, after the laminated raw sheet of the foamed resin sheet S and the decorating material 23 is put into the molding upper and lower molds 41 and 42 in the mold open state, as shown in FIG. The mold 41 is lowered by a predetermined stroke, the mold is clamped, and the foamed resin sheet S is drawn into a required shape, and the decorating material 23 affixed to the surface of the foamed resin base material 21 has a vacuum action, The molding is accurately performed along the mold surface shape of the cavity portion 411 of the upper mold 41, and the drawn pattern is also accurately transferred. In addition, as the foamed resin sheet S used in this embodiment, a polypropylene foam sheet (manufactured by Sumika Plustech, trade name: Sumiceller foam PP sheet, expansion ratio = 3 times, thickness 3 mm) is used. The press pressure when the upper mold 41 is clamped to the lower mold 42 is a low pressure press of 0 to 40 kgf / cm ² , and the normal press pressure of the conventional mold press molding is 80 ± 20 kgf. Compared with / cm ² , the pressing pressure can be reduced, and the load during molding can be reduced.

  Further, when the molding of the foamed resin base material 21 and the decorating material 23 is completed, as shown in FIG. 8, the molten resin M is introduced into the rib forming groove 424 from the injection machine 43 through the hot runner 422 and the valve gate 423. Injection filled. At this time, as compared with the conventional resin core material having a large projected area, since only the resin for forming the thin resin rib 22 is injected, the injection pressure of the resin can be set low. It is clear that it is not necessary to apply a high press pressure to the resin, and it is sufficient that a press pressure sufficient to form the foamed resin base material 21 and the decorating material 23 is applied. Note that the injection timing of the molten resin M can be set before the mold upper and lower molds 41 and 42 are clamped. As the molten resin M, Sumitomo Noblen BUE81E6 (polypropylene manufactured by Sumitomo Chemical Co., Ltd., melt index = 65 g / 10 min), in which talc is mixed at an appropriate ratio, is used.

  As described above, the molding of the door trim upper 20 is completed by integrally molding the resin rib 22 on the back surface of the foamed resin base material 21 after the integral press molding of the foamed resin base material 21 and the decorating material 23. Then, as shown in FIG. 9, when the molding die 40 is opened after the molding is completed, the undercut portion A is removed from the undercut convex portion 418 by the elastic deformation of the decorative material 23, particularly the cushion layer 23b. The undercut portion A can be molded and removed smoothly even if the molding die 40 having a simple structure that eliminates the cylinder-driven undercut nesting can be easily removed. Furthermore, the foamed resin base material 21 can be expected to exhibit a slight elastic action, and therefore the undercut portion A can be more easily removed from the mold 40 due to the synergistic effect of both. In the above-described configuration, only the door trim upper 20 is molded by the molding die 40. However, the molding of the door trim upper 20 and the molding of the door trim lower 30 may be performed in the same mold. A two-shot cylinder type mold may be used.

  In the embodiment described above, the laminated structure according to the present invention is applied to the door trim upper 20 in the door trim 10 having the upper and lower divided structures, but the entire door trim 10 may be constituted by the laminated structure. In addition, if it is a laminated structure of foamed resin base material 21, resin rib 22, and decorating material 23, it is applied to all interior trims such as rear parcel shelf, floor trim, trunk trim, rear side trim, pillar garnish, roof trim, etc. In particular, it can be effectively applied to interior parts having an undercut portion.

It is a front view which shows the Example which applied the interior component for motor vehicles which concerns on this invention to the door trim for two-tone type vehicles. It is the II-II sectional view taken on the line in FIG. It is a front view which shows the resin rib and door trim lower of the door trim upper in the door trim for motor vehicles shown in FIG. It is sectional drawing which shows the structure of the door trim upper in the door trim for motor vehicles shown in FIG. It is a schematic diagram which shows the whole structure of the shaping die which shape | molds the door trim upper shown in FIG. It is explanatory drawing which shows the in-mold setting process of the raw material in the molding method of the door trim upper shown in FIG. It is explanatory drawing which shows the formation process of the foaming resin base material in the molding method of the door trim upper shown in FIG. 4, and a decorating material. It is explanatory drawing which shows the injection filling process of the resin rib in the molding method of the door trim upper shown in FIG. It is explanatory drawing which shows the demolding process of the door trim upper in the shaping | molding method of the door trim upper shown in FIG. It is a front view which shows the conventional door trim for motor vehicles. It is sectional drawing which shows the structure of the conventional door trim for motor vehicles. It is explanatory drawing which shows the shaping die at the time of carrying out the mold press molding of the conventional door trim. It is sectional drawing which shows the weight-reduced door trim of the conventional upper and lower divided type. It is composition explanatory drawing which shows the light weight door trim of the conventional upper and lower divided type. It is explanatory drawing which shows the shaping | molding metal mold | die which shape | molds the door trim upper in the conventional light weight door trim of the upper and lower divided type.

Explanation of symbols

10 Automotive Door Trim 20 Door Trim Upper (Laminated Structure)
21 Foamed resin base material 22 Resin rib 23 Decorating material 23a Top layer 23b Cushion layer 30 Door trim lower (single resin)
40 Molding die 41 Molding upper die 411 Cavity part 412 Elevating cylinder 413 Vacuum chamber 414 Vacuum suction hole 418 Undercut convex part 42 Molding lower mold 421 Core part 422 Hot runner 423 Valve gate 424 Rib forming groove part 43 Injection machine A Under Cut part S Foamed resin sheet M Molten resin

Claims (1)

A foamed resin base material (21) which is molded into a required shape and is lightweight and has shape retention, and a resin rib (22) having a predetermined pattern shape laminated and integrated on the back surface of the foamed resin base material (21) In the interior part (10) for an automobile, in which the laminated structure (20) composed of the decorating material (23) attached to the surface of the foamed resin base material (21) is employed in whole or in part.
The decorative material (23) in the laminated structure (20) is composed of a laminated structure of at least two layers of a top layer (23a) and a cushion layer (23b), and is a foamed resin sheet (heat softening treated in advance) S) and the decorating material (23) are put into the molding dies (41, 42), and the molding material (41, 42) is clamped on the surface of the foamed resin base material (21). 23) is formed into a required shape in a state of being laminated and integrated, and the undercut portion (A) is formed by the undercut convex portion (418) provided in the molding die (41) on one side. And the laminated structure (20) is set by setting the thickness (d1) of the cushion layer (23b) in the decorating material (23) to be thicker than the undercut amount (d) of the undercut portion (A). Of undercut part (A) Automotive interior parts, characterized in that it made it possible to create.

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