JP2007091097A - Interior part for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a peeling failure between a resin rib and a foaming resin base material on an interior part for an automobile for the whole or a part of which a laminated structural body made of the foaming resin base material and the resin rib integrated on the back surface side of it is adopted. <P>SOLUTION: A door trim 10 is constituted of a door trim upper (laminated structural body) 20 and a door trim lower (resin simplex article) 30. The door trim upper 20 is constituted of the laminated structural body of the foaming resin base material 21 light in weight and having shape retaining performance and the resin rib 22 integrated on the inner surface side of the foaming resin base material 21, and it is possible to prevent the breakage of the resin rib 22 since the rib depth of the resin rib 22 is set 3 to 7mm and a tensile force can be reduced when a load is applied on the product surface of the door rim upper 20. Additionally, it is possible to uniform rigidity and to properly secure the flowing length of resin in setting the rib width 3 to 7mm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to automotive interior parts such as door trims, rear parcel shelves, floor trims, trunk trims, luggage trims, roof trims, rear side trims, and the like, and are interior parts for automobiles that are lightweight and have improved exterior design and product rigidity. About.

  For example, the configuration of automobile interior parts will be described with reference to FIGS. 14 and 15 exemplifying door trims. 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. . The resin core material 2 is made of a polypropylene resin mixed with talc, and the skin 3 does not have shape retention itself, such as polyethylene foam on the back surface of a synthetic resin sheet such as a vinyl chloride sheet. In recent years, considering the environmental and recycling aspects, a cushioning material such as polyethylene foam is provided on the back surface of an elastomer sheet such as a thermoplastic olefin (hereinafter referred to as TPO) sheet. Laminated sheet material tends to be frequently 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 that molds the door trim 1 is connected to a molding upper die 5 that can move up and down by a predetermined stroke, a molding lower die 6 that forms a pair with the molding upper die 5, and a molding lower die 6. It is generally composed of the injection machine 7. Then, when the upper and lower molds 5 and 6 are clamped, a cavity part 5a is formed in the upper mold 5 and a core part 6a is provided in the lower mold 6 in order to form the product shape of the door trim 1. Yes. In order to move the molding upper die 5 up and down by a predetermined stroke, an elevating cylinder 5b is connected, and the molding lower die 6 is provided with a manifold 6b and a gate 6c serving as a passage for the molten resin M from the injection machine 7. Further, in order to maintain an appropriate posture, the molding upper die 5 that moves up and down is provided with guide posts 6d at four corners of the molding lower die 6, and the molding upper die 5 corresponds to the guide posts 6d. A bush 5c is provided.

  Accordingly, when the molding upper and lower molds 5 and 6 are in the mold open state, the skin 3 is set in the mold, the molding upper and lower molds 5 and 6 are clamped, and then the injection machine 7 is placed in the product cavity between both molds. The resin core material 2 is molded into a required curved shape by injection and filling the molten resin M through the manifold 6b and the gate 6c, and the skin 3 is integrally molded on the surface of the resin core material 2 (for example, patent Reference 1). In FIG. 16, for convenience of explanation, the molten resin M is supplied to the mold surface of the core portion 6 a in an open state. However, the molten resin M is injected and filled into the cavity after the mold upper and lower molds 5 and 6 are clamped. May be.

Japanese Patent Laid-Open No. 10-138268 (Page 2, FIGS. 3 and 4)

  However, in the conventional door trim 1, since the projected area of the resin core material 2 is large, 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, and the production cost of the mold is increased, In addition, since a large amount of molten resin is cooled and solidified, the molding cycle becomes longer, which is a major factor for reducing productivity.

  The present invention has been made in view of such circumstances, and relates to automotive interior parts such as door trims, and in particular, can promote weight reduction, reduce costs, and improve appearance quality and product rigidity. The purpose is to provide automotive interior parts.

  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. Compared to conventional resin cores with a large projected area, resin ribs with excellent rigidity are placed in places where rigidity is required, that is, peripheral parts of products, panels, parts mounting locations, and parts where loads are applied. Providing a lightweight and low-cost laminated structure, and by appropriately setting the dimensions such as the rib depth and rib width of the resin rib, it is possible to reliably prevent the resin rib from being damaged when a load is applied. As a result, the present invention has been completed.

  In order to solve the above-described problems, the present invention provides a foamed resin base material that is molded into a required shape and is lightweight and has shape retention, and a resin rib having a predetermined pattern shape that is integrated with the back surface of the foamed resin base material. In the interior part for automobiles, in which the laminated structure composed of the above is adopted in whole or in part, the rib depth of the resin rib in the laminated structure is set to 3 to 7 mm.

  Here, the interior parts for automobiles can be applied to door trims, rear parcel shelves, floor trims, trunk trims, luggage trims, roof trims, rear side trims, and the like. Further, the structure of the present invention can be applied to the entire structure of the interior parts for automobiles, and the structure of the present invention can be applied only to a part of the interior parts for automobiles, for example, the door trim upper in the upper and lower door trim. it can.

  Furthermore, the foamed resin base material having the shape retaining property can be obtained after the foamed resin sheet is heat-softened and then molded into a desired curved shape in a molding die, so that there is no reinforcing material such as a rib. , Has rigidity (shape retention) enough to retain the shape even when removed from the mold. Also, if the product shape includes a high expansion ratio part, after the foamed resin sheet is heat-softened, a vacuum suction mechanism is provided in the molding die and the foamed resin sheet is vacuumed along the inner surface of the molding die. A suction force may be applied.

  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, polyethylene terephthalate resin, polyvinyl alcohol resin, vinyl chloride resin, polyamide resin, polyacetal resin, polycarbonate resin, ionomer resin, acrylonitrile / butadiene / Styrene (ABS) resin or the like can be used. As the foaming agent, an organic foaming agent such as an azo compound, 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 having a reinforcing function 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, polyethylene terephthalate resins, polyvinyl alcohol resins, vinyl chloride resins, polyamide resins, polyacetal resins, polycarbonate resins, ionomer resins, Examples include acrylonitrile / butadiene / styrene (ABS) resin. 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 in order to improve an external appearance design property, you may laminate | stack and integrate a decorating material on the surface of a foamed resin base material. Examples of this decorating material include TPO sheets, TPU (thermoplastic urethane) sheets, synthetic resin sheets such as PVC sheets, fabric sheets such as woven fabrics, nonwoven fabrics, and knitted fabrics, or synthetic resin films, foams, nets, etc. Can be used in the form of a single sheet, or in the form of a laminated sheet material in which a back surface of a synthetic resin sheet or a fabric sheet is lined with a cushioning material such as polyethylene foam, polypropylene foam or polyurethane foam. Although the material which comprises these decorating materials is not specifically limited, It is more preferable to use the raw material which has air permeability, such as a woven fabric, a nonwoven fabric, and a knitted fabric, in order to utilize the sound absorption performance of a foamed resin base material.

  In addition, the porous sound-absorbing function of the foamed resin base material provides interior parts with excellent sound-absorbing performance. When polyolefin resin is used as the material for the foamed resin base material and resin rib, all-olefin resin is unified. Therefore, the separation process can be abolished and the recycling work can be simplified.

  Furthermore, a laminated structure is composed of a foamed resin base material and a resin rib integrated on the back surface of the foamed resin base material. When a load is applied to the laminated structure, the tensile force applied to the resin rib is increased. Since it is small, breakage of the resin rib can be prevented as much as possible, and since the rib depth is shallow, the panel space can be small. At this time, the rib depth of the resin rib is set to 3 to 7 mm, preferably 5 mm. However, when the rib depth is less than 3 mm, the function of reinforcing the foamed resin base material cannot be obtained. On the other hand, when the rib depth exceeds 7 mm, there is a problem that the pulling force when a load is applied is increased and the rib breakage is easily induced.

  Next, a molding die used for molding the laminated structure is a laminated structure composed of a lightweight foam resin base material having shape retention and a resin rib integrated on the back surface of the foam resin base material. A molding die for molding a body, the molding die being connected to the molding upper die and the molding lower die which can be clamped and opened with each other, and a molten resin which is a material of the resin rib And an injection machine for supplying.

  Here, the molding die is composed of a molding upper mold that can move up and down, a molding lower mold that is a fixed side located below the molding upper mold, and an injection machine that is connected to the molding lower mold. . The molten resin supplied from the injection machine is supplied to a groove formed on the mold surface of the molded lower mold through a resin passage such as a manifold and a gate provided in the molded lower mold. In addition, the foamed resin sheet is shaped along the shape of the mold surface of the molding die by clamping the molding die. At that time, a heat softening process is performed by a heater or the like before the molding process. The heat-softened foamed resin sheet is set in a molding die. The molding process of the foamed resin sheet with the molding die includes a cooling process of the foamed resin sheet. In addition to cooling by molding mold clamping, the foaming resin sheet is forced. Alternatively, it may be cooled. For example, heat may be released by providing a predetermined clearance between the foamed resin base material and the mold surface of the molded lower mold, and coolant such as cooling air is blown from the back side of the foamed resin base material. Thus, the foamed resin base material can be effectively cooled. In this case, the air blow may be performed in a mold-clamped state, or the upper mold is raised so that a clearance is provided between the foamed resin base material and the lower mold, and air is blown into the clearance. Also good.

  Therefore, according to the present invention, it is only necessary to mold the resin rib as compared with the conventional resin core material having a large projected area, so that the injection pressure can be set lower than the conventional one, and the load on the molding upper mold is reduced. Less material is required and material costs can be saved. Furthermore, in the present invention, since the rib depth of the resin rib is set as shallow as 3 to 7 mm, the tensile force when a load is applied is reduced, and the rib breakage can be prevented as much as possible. Less panel space between panels and excellent space performance.

  In a further preferred embodiment of the present invention, the rib width of the resin rib in the laminated structure is set to 3 to 7 mm. And according to this embodiment, since the rib width of the resin rib is set as wide as 3 to 7 mm, the rigidity can be enhanced even if the rib depth is set shallow, and the flow of the resin The length can be effectively secured, filling defects such as short shots can be prevented, and molding stability is improved.

  As described above, according to the automotive interior component according to the present invention, the laminated structure constituting the entirety or a part of the automotive interior component is a lightweight and shape-retaining foamed resin base material, Because it is composed of resin ribs integrated with the back of the foamed resin base material, the conventional heavy resin core material can be abolished. Has the effect of providing excellent automotive interior parts.

  Furthermore, according to the automotive interior part of the present invention, since the rib depth of the resin rib in the laminated structure is set to be relatively shallow, such as 3 to 7 mm, the tensile force when a load is applied is small. The ribs can be prevented from being damaged as much as possible, and the panel space can be reduced, resulting in excellent space performance.

  In addition, when the rib depth of the resin rib is set to be shallow and at the same time the rib width is set to be as wide as 3 to 7 mm, the rigidity can be strengthened and the resin flow length can be ensured satisfactorily. Therefore, it is possible to eliminate molding defects such as short shots and to improve the moldability such as shortening the cycle time.

  Hereinafter, a preferred embodiment of an automobile interior part according to the present invention will be described by illustrating an automobile door trim. Note that the gist of the present invention is as described in the scope of claims, and the contents of the embodiments described below are merely examples of the present invention.

  FIG. 1 to FIG. 13 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 sectional view showing the configuration of the automobile door trim, and FIG. FIG. 4 and FIG. 5 are cross-sectional views showing the main components of the door trim upper in the automotive door trim, and FIG. 6 shows a state in which a load is applied to the door trim upper. FIG. 7 to FIG. 9 show a molding die used when molding the automobile door trim, FIG. 7 is an overall view of the molding die, and FIGS. 8 and 9 are door trims in the molding die. It is each sectional drawing which shows an upper formation part. Further, FIGS. 10 to 13 show the respective steps of the manufacturing method of the automobile door trim, FIG. 10 is a preheating step of the foamed resin sheet, FIG. 11 is a step of setting the foamed resin sheet to the molding die, and FIGS. 13 is explanatory drawing which respectively shows the shaping | molding process of a door trim.

  First, based on FIG. 1 thru | or FIG. 6, the structure of the two-tone type vehicle door trim 10 to which the structure of the interior component for motor vehicles which concerns on this invention is applied is demonstrated. The two-tone type automobile door trim 10 is composed of an upper and lower divided body including a door trim upper 20 made of a laminated structure and a door trim lower 30 made of a single resin. And as a functional component with which the door trim 10 is mounted | worn, the inside handle escutcheon 11 and the power window switch escutcheon 12 are attached to the door trim upper 20. FIG. The door trim lower 30 is provided with a door pocket opening 13, and a pocket back cover (made of a resin molded body) 14 is attached to the rear side thereof as shown in FIG. The speaker grill 15 is provided integrally with the door trim lower 30 or separately on the front side of the door 30.

  By the way, the automotive door trim 10 according to the present invention is characterized by the structure of the door trim upper 20 formed of a laminated structure, and the weight of the product is reduced, and a good surface appearance and strong product rigidity are ensured. ing. That is, as shown in FIG. 2, the door trim upper 20 is formed into a desired curved surface shape, and has a foamed resin base material 21 having shape retention, and a resin rib integrated with the back surface side of the foamed resin base material 21. 22 and a decorating material 23 having a decorating function that is laminated and integrated on the surface side of the foamed resin base material 21. In the figure, reference numeral 16 denotes a vehicle body panel.

  The foamed resin base material 21 has a shape after heat-softening treatment of the foamed resin sheet and heat molding into a required shape, for example, cold press molding with a molding die having a desired mold surface, so as to have shape retention. Is granted. The foamed resin sheet has a structure 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 polyethylene terephthalate resin, a polyvinyl alcohol resin, a chloride resin. Vinyl resin, polyamide resin, polyacetal resin, polycarbonate resin, ionomer resin, acrylonitrile / butadiene / styrene (ABS) resin, etc. can be used. As the foaming agent, 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. Moreover, the expansion ratio of the foamed resin base material 21 is set to 2 to 10 times, and the thickness is set to 0.5 to 30 mm, particularly preferably 1 to 10 mm.

  Next, as shown in FIG. 3, the resin ribs 22 are set in a lattice pattern extending in the vertical and horizontal directions or in an oblique direction. And this resin rib 22 consists of a general-purpose synthetic resin molding, and as a synthetic resin which can be preferably used normally, polyethylene resin, polypropylene resin, polystyrene resin, polyethylene terephthalate resin, polyvinyl alcohol resin, vinyl chloride resin Resin, polyamide-based resin, polyacetal-based resin, polycarbonate-based resin, ionomer-based resin, acrylonitrile / butadiene / styrene (ABS) resin, and the like may be appropriately selected. In this embodiment, polypropylene is considered in consideration of environmental aspects and recycling aspects. System resin 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 made of a laminated structure and the door trim lower 30 which is a single synthetic resin, and has an excellent appearance design due to an accent effect on the appearance. It has sex. Furthermore, since the door trim upper 20 is composed of a foamed resin base material 21 having shape retention and a resin rib 22 laminated and integrated on the back surface of the foamed resin base material 21, it is provided on the entire surface of the product as in the past. The resin core material that has been occupied can be abolished and the lightweight foamed resin base material 21 is used. On the other hand, the resin rib 22 has a bone shape and is subjected to a load, such as a clip mounting seat, a waist flange, an armrest portion. The parts excluding the top surface have a thinned structure, so that the weight of the product can be reduced by 40% or more compared to the conventional example, and the resin material can be saved significantly. Can contribute to down.

  Furthermore, since the foamed resin base material 21 has a porous structure, the door trim upper 20 has excellent sound absorption performance and can reduce noise inside and outside the vehicle interior. Further, if desired, a decorative material may be laminated and integrated on the surface of the foamed resin base material 21. In that case, in order to improve the sound absorption performance for vehicle interior noise, the decorative material laminated and integrated on the surface of the foamed resin base material 21 has air permeability such as a woven fabric, a non-woven fabric, and a knitted fabric. Sheet material is preferred. In addition to the breathable sheets such as woven fabric, non-woven fabric, and knitted fabric, the decorative material is a synthetic resin sheet such as a vinyl chloride sheet and a TPO sheet (recyclable if a TPO sheet is used), a synthetic resin film, and a foam. A net or the like can be used. In addition, as a low-cost configuration, the decorating material may be omitted, and the surface of the foamed resin base material 21 may be subjected to painting or printing processing.

  Next, structural features of the door trim 10 to which the present invention is applied will be described with reference to FIGS. That is, the present invention is characterized in that the rib depth d of the resin rib 22 in the foamed resin base material 21 is set to 3 to 7 mm. For example, as shown in FIG. 6, if a load F is applied in a state where the resin rib 22 is supported at two support points P, a pressing force is applied to the resin rib 22 in the direction of arrow A and a tensile force is applied in the direction of arrow B. Will be added. At this time, since the rib depth d is set to 3 to 7 mm, preferably 5 mm, the pulling force when the load F in FIG. Can be prevented. In addition, since the rib depth d of the resin rib 22 is shallow, the bending load strength becomes weak. However, the rigidity can be increased by actually setting the rib width wide and the rib pitch narrow, and the amount of fracture displacement is growing. Therefore, since the resin rib 22 according to the present invention is not easily cracked, a uniform rigidity can be obtained as a product. Further, since the rib depth d is shallow, such as 3 to 7 mm, there is an advantage that the clearance with the vehicle body panel is small and the space performance is excellent.

  As described above, the rib depth d of the resin rib 22 is set in the range of 3 to 7 mm. However, when the rib depth d of the resin rib 22 is less than 3 mm, it does not serve as a reinforcing rib. Conversely, when the rib depth d exceeds 7 mm, the resin rib 22 tends to be damaged when a load is applied. Further, in this embodiment, the rib depth d of the resin rib 22 is set to a short dimension of 3 to 7 mm, and at the same time, the rib width w of the resin rib 22 is also 3 to 7 mm, preferably 5 mm. Moreover, it is characterized by being set relatively wide. Therefore, since the rib width w is relatively wide, the product rigidity can be secured satisfactorily even when the rib depth of the resin rib 22 is shallow. In particular, since the rib width w of the resin rib 22 is wide, the resin flow length Can be effectively secured, short shots can be prevented more reliably, and the cycle time can be shortened, and the moldability can be improved.

  Next, a method for forming the door trim 10 including the door trim upper 20 and the door trim lower 30 configured as described above will be described below. Before that, the structure of the molding die 40 will be described with reference to FIGS. In FIG. 7, a molding die 40 used for molding the door trim 10 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 a molding lower mold 42. It consists of two injection machines 43a and 43b connected to each other. More specifically, the molding upper die 41 has a cavity portion 411 that matches the product shape, and 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. In addition, guide bushes 413 serving as a guide mechanism are provided at the four corners of the molding upper die 41.

  On the other hand, the molding lower die 42 is provided with a core portion 421 corresponding to the cavity portion 411 of the molding upper die 41. In addition, manifolds 422a and 422b and gates 423a and 423b are provided to supply molten resin to the mold surface of the core portion 421, and the injection machine passes through the resin passages of the manifolds 422a and 422b and gates 423a and 423b. Molten resins M1 and M2 supplied from 43a and 43b are supplied to the upper surface of the core portion 421. In order to form the resin rib 22, a groove 424 to which the molten resin M <b> 1 is supplied is formed on the upper surface of the core portion 421, while a predetermined portion is formed between the upper and lower molds 41 and 42 to form the door trim lower 30. A clearance cavity 425 is set. In addition, guide posts 426 that serve as a guide mechanism protrude from the four corners of the molded lower mold 42, and the guide posts 426 guide into the guide bush 413 when the molded upper and lower molds 41 and 42 are clamped. As a result, the pressing posture of the molding upper die 41 can be properly maintained.

  Further, as shown in FIGS. 8 and 9, a groove portion 424 corresponding to the pattern shape of the resin rib 22 is provided in the molding lower die 42 corresponding to the door trim upper 20. The dimensions of the groove portion 424 are as follows. Since the rib depth d of the resin rib 22 is set to be relatively shallow such as 3 to 7 mm, the groove depth of the groove portion 424 is also set to 3 to 7 mm, and FIG. As shown, the groove width of the groove portion 424 is also set to be relatively wide, such as 3 to 7 mm. In addition, although not shown, the molding lower mold 42 may be provided with an air blow mechanism. As an air blow mechanism, a compressed air blower and an air blow pipe connected thereto communicate with the molding lower mold air chamber, and an open / close valve provided in the air blow pipe opens and closes the refrigerant in the air chamber of the molding lower mold 42. As the cooling air is supplied, the cooling air is blown into the cavity through the air blow holes formed in the mold surface of the molding lower mold 42. As the refrigerant, liquid nitrogen, liquid air, carbon dioxide or the like can be used in addition to the cooling air.

  Next, a method for manufacturing the door trim 10 described above will be briefly described with reference to FIGS. First, as shown in FIG. 10, the preheating process of the foamed resin sheet S which heat-softens the foamed resin sheet S to predetermined temperature with the heater apparatus 50 is employ | adopted. 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 as the foam resin sheet S. 11, the upper half of the cavity defined by the cavity portion 411 of the molding upper die 41 and the core portion 421 of the molding lower die 42 at the location corresponding to the door trim upper 20 is applied to the heat-softened foamed resin sheet S. Set to part. A decorative material 23 is laminated in advance on one surface of the foamed resin sheet S. After the foamed resin sheet S is set, as shown in FIG. 12, the raising and lowering cylinder 412 of the molding upper die 41 is operated, the molding upper die 41 is lowered by a predetermined stroke, and the molding upper and lower dies 41 and 42 are clamped. Then, the foamed resin sheet S is shaped along the cavity shape.

  Next, after forming the foamed resin base material 21 into a desired curved surface shape from the foamed resin sheet S, as shown in FIG. 13, the resin ribs 22 in the door trim upper 20 from the first injection machine 43a through the manifold 422a and the gate 423a. In order to form the molten resin M1, the groove portion 424 and the terminal portion 424a of the lower mold 42 are injected and filled. Further, in order to form the door trim lower 30, the molten resin M2 is injected and filled into the cavity 425 from the second injection machine 43b through the manifold 422b and the gate 423b, and the door trim lower 30 is formed into a required shape. As the molten resins M1 and M2, a resin material in which a filler such as talc is mixed in an appropriate proportion to Sumitomo Nobrene BUE81E6 (polypropylene manufactured by Sumitomo Chemical Co., Ltd., melt index = 80 g / 10 min) is used. . Accordingly, the molten resin M1 is injected and filled into the groove portion 424 and the terminal portion 424a from the first injection machine 43a, while the molten resin M2 is injected and filled into the cavity 425 from the second injection machine 43b. The resin rib 22 is formed into a required shape, and the door trim lower 30 is integrally formed therewith.

  When the molten resin M1 is injected and filled into the groove portion 424 of the molding lower mold 42, the groove depth of the groove portion 424 is particularly shallow and the groove width is set wide. It will spread quickly, avoiding filling defects such as short shots and shortening the shot cycle. In addition, since the molten resin M1 spreads effectively, the flow length can be set relatively long, and the setting position of the gate can be freely set.

  Thus, especially the door trim 10 for motor vehicles based on this invention is comprised from the foamed resin base material 21 and the resin rib 22 integrated on the back surface as a structure of the door trim upper 20, and weight reduction is carried out. In particular, the rib depth d of the resin rib 22 in the door trim upper 20 is set to be relatively shallow, such as 3 to 7 mm, so that damage to the rib when a load is applied can be prevented as much as possible. Good rigidity can be maintained for a long time. In addition, when the rib width w is set to be as wide as 3 to 7 mm, the product rigidity can be made uniform and the moldability can be improved, such as ensuring the resin flow length. There is also an effect.

  In the embodiment described above, the structure of the present invention is applied to the door trim upper 20 in the two-tone type automobile door trim 10, but the interior door trim or the interior parts other than the door trim, such as the rear parcel shelf, the floor trim, and the trunk trim. The structure of the present invention can be applied to interior trims such as luggage trim, roof trim, rear side trim, and the like.

It is a front view which shows the door trim which is one Example of the interior component for motor vehicles based on this invention. 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 shown in FIG. It is sectional drawing which shows the principal part structure of the door trim upper in the door trim shown in FIG. FIG. 5 is a sectional view taken along line V-V in FIG. 4. It is explanatory drawing which shows the state which applied the load to the resin rib in the door trim shown in FIG. It is explanatory drawing which shows the whole structure of the molding die used when shape | molding the door trim shown in FIG. It is principal part sectional drawing which shows the shape of the groove part in the shaping die shown in FIG. It is the IX-IX sectional view taken on the line in FIG. It is explanatory drawing which shows the preheating process of the foamed resin sheet in the manufacturing method of the door trim shown in FIG. It is explanatory drawing which shows the in-mold setting process of the foamed resin sheet in the manufacturing method of the door trim shown in FIG. It is explanatory drawing which shows the formation process of the foamed resin base material in the manufacturing method of the door trim shown in FIG. It is explanatory drawing which shows the formation process of the resin rib of the door trim upper in the manufacturing method of the door trim shown in FIG. 1, and the formation process of a door trim lower. It is a front view which shows the conventional door trim. It is the XV-XV sectional view taken on the line in FIG. It is explanatory drawing which shows the structure of the shaping die used when shape | molding the conventional door trim.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Two-tone type automobile door trim 20 Door trim upper 22 Resin rib 23 Decorating material 24 Boss 30 Door trim lower 40 Molding die 41 Molding upper mold 42 Molding lower mold 424 Groove 43a, 43b Injection machine M1, M2 Molten resin S Foamed resin sheet d Rib depth w Rib width

Claims (2)

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 integrated with the back surface of the foamed resin base material (21). In an automotive interior part (10) formed by adopting the laminated structure (20) in whole or in part,
The interior part for automobiles, wherein the rib depth (d) of the resin rib (22) in the laminated structure (20) is set to 3 to 7 mm. The automotive interior part according to claim 1, wherein a rib width (w) of the resin rib (22) in the laminated structure (20) is set to 3 to 7 mm.

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