JP2008055848A - Interior component for automobile and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the shrinkage strain of a resin rib and prevent the surface sink in an interior component for an automobile and its manufacturing method where a laminated structure composed of a foamed resin substrate and the resin rib integrated on the back surface side is adopted as a whole or in a part. <P>SOLUTION: A door trim 10 is composed of a door trim upper (a laminated structure) 20 and a door trim lower (formed only from a resin) 30. The door trim upper 20 is composed of the laminated structure of a foamed resin substrate 21 of light weight and shape retention and the resin rib 22 integrated on its inner surface side. The shrinkage stain after molding of the resin rib 22 is suppressed and the surface sink is surely prevented by using a composite resin material made of reinforced fiber (a) such as glass fiber and thermoplastic resin as a raw material of the resin rib 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to automobile interior parts such as door trims, rear parcel shelves, floor trims, trunk trims, luggage trims, roof trims, rear side trims, and manufacturing methods thereof, and is a light-weight automobile with improved appearance design and product rigidity. The present invention relates to interior parts for automobiles and methods for producing the same.

  For example, the configuration of automobile interior parts will be described with reference to FIGS. 11 and 12 exemplifying a door trim. 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. When the upper and lower molds 5 and 6 are clamped, a cavity portion 5a is formed in the molded upper mold 5 and a core section 6a is provided in the molded lower mold 6 in order to shape 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 upper molding die 5 that moves up and down is provided with guide posts 6d at the four corners of the lower molding die 6, and the molding upper die 5 has guides corresponding 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. 13, for convenience of explanation, the molten resin M is supplied to the mold surface of the core portion 6 a in an open state, but 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 a method for manufacturing the same. In particular, the present invention can promote weight reduction, reduce costs, and improve appearance quality and product rigidity. An object of the present invention is to provide an automotive interior part and a method for producing the same.

  As a result of earnest research, the present inventors have given the function as a core material by imparting shape-retaining properties 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. In addition to providing a light-weight and low-cost laminated structure, the present invention is completed by focusing on the fact that shrinkage distortion after molding of the resin rib can be suppressed by adding ingenuity to the material of the resin rib. It came to.

  That is, the present invention relates to a laminated structure comprising a foamed resin base material that is molded into a required shape and is lightweight and has shape retention, and resin ribs having a predetermined pattern shape integrated with the back surface of the foamed resin base material. In the interior parts for automobiles, which are employed in whole or in part, the foamed resin base material in the laminated structure is molded into a required shape by a clamping press pressure between the upper and lower molds, while the resin rib is The molded resin is molded by injection-filling molten resin mixed with reinforcing fibers into the groove of the lower mold, so that the rigidity is strengthened and the resin ribs are mixed into the molten resin when the resin ribs are cooled and solidified. Shrinkage distortion is suppressed by the fibers.

  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, as the thermoplastic resin material used as the resin rib having a reinforcing function, a composite resin material in which a thermoplastic resin and a reinforcing fiber are mixed is used. The thermoplastic resin material can be appropriately selected from a wide range of 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.

  Furthermore, glass fiber and natural fiber can be used as the reinforcing fiber to be mixed. As a glass fiber, it is good to mix the glass fiber which has a fiber length of 5-20 mm with the mixture ratio of 5-20 weight part. This is because if the fiber length is less than 5 mm, the effect of suppressing the shrinkage is small, and conversely if the fiber length exceeds 20 mm, the fluidity of the resin is impaired and it is difficult to inject from the injection machine. Moreover, as natural fiber, bamboo, basalt, kenaf, or the like can be used. Furthermore, various additives such as an antioxidant, an ultraviolet absorber, a colorant, and a flame retardant may be blended as additives.

  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.

  Next, a method for manufacturing an automotive interior part according to the present invention includes a foamed resin base material that is molded into a required shape and is lightweight and has shape retention, and a predetermined pattern shape that is integrated on the back surface of the foamed resin base material. In a method for manufacturing an interior part for an automobile, in which a laminated structure composed of resin ribs is employed in whole or in part, the laminated structure heat-softens the foamed resin sheet that is the material of the foamed resin base material. After processing, the mold is put into a mold upper and lower molds in an open state, and the mold upper and lower molds are clamped to mold the foamed resin base material, which is press-molded into a required shape, and the mold upper and lower molds are clamped. At the same time, the molten resin mixed with the reinforcing fibers is injected and filled into the groove portion of the molding lower mold from the injection machine, and further, the molten resin is cooled and solidified to integrate the resin rib on the back surface of the foamed resin base material. Strong mixed with molten resin It is manufactured from a resin rib molding process that molds resin ribs while suppressing shrinkage distortion during cooling and solidification of resin ribs with fibers and restricting the boundary surface between the foam resin base material and resin ribs to be almost flat. It is characterized by that.

  Here, the molding die used when molding the laminated structure is a laminate composed of a foamed resin base material that is lightweight and has shape retention, and a resin rib that is integrated with the back surface of the foamed resin base material. A molding die for molding a structure, wherein the molding die is connected to the molding upper mold and the molding lower mold that can be clamped and opened with each other, and is a material of resin ribs that is connected to the molding lower mold. It is comprised from the injection machine which supplies resin. 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, a molten resin material mixed with reinforcing fibers is used as a material for the resin ribs, so that the shrinkage distortion after the molding of the resin ribs is suppressed by the reinforcing fibers, and the occurrence of sink marks on the product surface is prevented as much as possible. It is possible to maintain a good appearance and to improve the product rigidity and the impact absorbing performance because the reinforcing fibers are mixed therein.

  As described above, according to the automotive interior part and the manufacturing method thereof according to the present invention, the laminated structure constituting the whole or a part of the automotive interior part is a foamed resin base that is lightweight and has shape retention. Because it is composed of a material and a resin rib that is integrated with the back surface of the foamed resin base material, the conventional heavy resin core material can be abolished, so it is lightweight, low-cost, and porous. In addition, there is an effect that it is possible to provide an automotive interior part having excellent sound absorption performance.

  Furthermore, according to the interior part for automobiles and the manufacturing method thereof according to the present invention, since a resin material obtained by mixing a reinforcing fiber such as glass fiber and a thermoplastic resin is used as a material for the resin rib, The shrinkage strain is kept low, and by suppressing the shrinkage strain, surface defects such as sink marks occurring on the surface of the product can be surely prevented, the rigidity of the resin ribs can be strengthened by the reinforcing fibers, and the impact absorption performance can be improved. For example, the quality performance can be improved.

  Hereinafter, a preferred embodiment of an automobile interior part and a method for manufacturing the same according to the present invention will be described with reference to 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. 10 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. 4 is a front view showing a resin rib and a door trim lower of a door trim upper in the door trim, FIG. 4 is a cross-sectional view showing a configuration of the door trim upper in the door trim for the automobile, and FIG. 5 is a molding die used when molding the door trim for the automobile FIG. 6 to FIG. 10 show each step of the manufacturing method of the automobile door trim, FIG. 6 shows the preheating process of the foamed resin sheet, and FIG. 7 shows the setting of the foamed resin sheet to the molding die. FIG. 8 is an explanatory diagram showing a door trim molding process, and FIGS. 9 and 10 are explanatory views showing a resin rib molding process.

  First, based on FIG. 1 thru | or FIG. 4, 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. Reference numeral 16 in the figure denotes a vehicle body panel, and the decorating material 23 is made of a laminated sheet material in which a cushion layer 23b made of polypropylene foam is laminated on the back surface of a top layer 23a made of a TPO sheet.

  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 which added reinforced fiber, such as glass fiber and a natural fiber, As a synthetic resin which can be preferably used normally, polyethylene resin, polypropylene resin, polystyrene resin, polyethylene The present embodiment may be appropriately selected from terephthalate resin, polyvinyl alcohol resin, vinyl chloride resin, polyamide resin, polyacetal resin, polycarbonate resin, ionomer resin, acrylonitrile / butadiene / styrene (ABS) resin, etc. In view of environmental and recycling aspects, polypropylene resins are used.

  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. In addition, as a low-cost configuration, the decorating material 23 may be omitted, and the surface of the foamed resin base material 21 may be subjected to painting or printing processing.

  Next, FIG. 4 is a cross-sectional view showing the configuration of the main part of the door trim upper 20, and the boundary surface A between the foamed resin base material 21 and the resin rib 22 is regulated to a substantially flat surface shape. In the product appearance, the occurrence of sink marks is not noticeable, and a good appearance appearance is secured. This is because, as a material of the resin rib 22, a thermoplastic fiber is mixed with a reinforced fiber (indicated by symbol “a” in FIG. 4) to suppress shrinkage strain after the resin rib 22 is molded. In this embodiment, a resin material containing 5 to 20 parts by weight of glass fiber having a fiber length of 5 to 20 mm is used as the reinforcing fiber a. The reason for specifying the fiber length of the glass fiber as 5 to 20 mm with respect to the total weight is that if the fiber length is less than 5 mm, the effect of suppressing shrinkage strain is small, and conversely the fiber length exceeds 20 mm. This is because in some cases, the fluidity of the resin when injected from the injection machine is adversely affected. Moreover, in Table 1, the data of shrinkage distortion (shrinkage rate) are shown with a comparative example. As a comparative example, (1) polypropylene resin not mixed with filler, (2) polypropylene resin mixed with talc as filler, then (1) polypropylene resin mixed with 5 parts by weight of glass fiber as an example of the present invention, (2) Each shrinkage value of the polypyroprene resin mixed with 20 parts by weight of glass fiber is shown. As is apparent from the results in Table 1, the shrinkage ratio decreases as the glass fiber blending ratio increases. However, when the blending ratio increases, the resin flowability is affected. It is preferable to determine the blending ratio in consideration of the balance between moldability and moldability. Further, when glass fiber is used, the rigidity of the resin rib 22 itself is enhanced and the impact resistance is also improved. In addition to glass fibers, natural fibers such as bamboo, basalt, and kenaf can be used.

  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 FIG. In FIG. 5, 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.

  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 to the air blower communicate with the air chamber of the molding lower mold 42, and an opening / closing operation of an opening / closing valve provided in the air blow pipe causes the air blow mechanism to enter the air chamber of the molding lower mold 42. Cooling air as a refrigerant is supplied, and cooling air is blown into the cavity through an air blow hole 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. 6, a preheating step of the foamed resin sheet S in which the foamed resin sheet S is heated and softened to a predetermined temperature by the heater device 50 is employed. 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. Then, as shown in FIG. 7, 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. 8, the raising / 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. 9, the resin rib 22 in the door trim upper 20 is passed from the first injection machine 43a through the manifold 422a and the gate 423a. Is formed, the molten resin M1 mixed with the reinforcing fiber a is injected and filled into the groove 424 of the molded lower mold 42. 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 appropriately mixed in Sumitomo Noblen BUE81E6 (polypropylene manufactured by Sumitomo Chemical Co., Ltd., melt index = 80 g / 10 min) is used. Therefore, the resin rib 22 in the door trim upper 20 is obtained by injecting and filling the molten resin M1 into the groove portion 424 from the first injection machine 43a while injecting and filling the molten resin M2 into the cavity 425 from the second injection machine 43b. Is molded into a required shape, and the door trim lower 30 is integrally molded therewith.

  Then, as shown in FIG. 10, molten resin M1 to which reinforcing fiber a (glass fiber in this embodiment) is added is injected and filled into the groove portion 424 of the molding lower mold 42, and cooled for a predetermined time. At the time of solidification, since the shrinkage strain is suppressed by the reinforcing fiber a, the boundary surface A between the resin rib 22 and the foamed resin base material 21 is not pulled toward the resin rib 22 side, and is regulated to a substantially flat surface shape. Therefore, sink marks or the like do not occur on the product surface of the door trim upper 20, and good appearance performance can be expected.

  As described above, the automobile door trim 10 according to the present invention promotes weight reduction by configuring the door trim upper 20 with the foamed resin base material 21 and the resin rib 22 integrated on the back surface thereof. At the same time, the resin rib 22 is made of a molten resin M1 in which a reinforced fiber a such as glass fiber and a thermoplastic resin are mixed, thereby improving rigidity and impact resistance and effectively reducing shrinkage strain after molding. There is an effect that the appearance of defects such as sink marks does not occur on the surface of the product, and a good appearance can be maintained over a long period of time.

  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. 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 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 door trim manufacturing method shown in FIG. 1, and a door trim lower. It is sectional drawing which shows the structure of the boundary part of the resin rib and foaming resin base material in the formation process of the resin rib shown in FIG. It is a front view which shows the conventional door trim. FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. 11. It is explanatory drawing which shows the structure of the shaping die used when shape | molding the conventional door trim.

Explanation of symbols

10 Two-tone type automobile door trim 20 Door trim upper 22 Resin rib 23 Decorating material 23a Top layer 23b Cushion layer 30 Door trim lower 40 Molding die 41 Molding upper die 42 Molding lower die 424 Groove 43a, 43b Injection machine A Interface M1 Melting Resin (with reinforcing fiber)
M2 Molten resin S Foamed resin sheet a Reinforcing fiber

Claims (3)

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 foamed resin base material (21) in the laminated structure (20) is molded into a required shape by a clamping press pressure between the molded upper and lower molds (41, 42), while the resin rib (22) is molded into the molded lower mold. The resin rib (22) is cooled while being molded by injection-filling molten resin (M1) mixed with reinforcing fibers (a) into the groove (424) of (42). An interior part for an automobile, wherein shrinkage distortion is suppressed by the reinforcing fiber (a) mixed in the molten resin (M1) during solidification.   The reinforcing fiber (a) mixed into the molten resin (M1) that is the material of the resin rib (22) has a fiber length of 5 to 20 mm and a blending ratio of 5 to 20 parts by weight with respect to the molten resin (M1). The interior part for automobiles according to claim 1, wherein the interior part is a glass fiber set to 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 integrated with the back surface of the foamed resin base material (21). In the manufacturing method of the automotive interior part (10) formed by adopting the laminated structure (20) in whole or in part,
The laminated structure is subjected to heat-softening treatment of the foamed resin sheet (S), which is the material of the foamed resin base material (21), and then charged into the mold upper and lower molds (41, 42) in the mold open state. A molding step of the foamed resin base material (21) that is press-molded into a required shape by clamping the upper and lower molds (41, 42);
The mold upper and lower molds (41, 42) are clamped and the molten resin (M1) mixed with the reinforcing fibers (a) is injected and filled from the injection machine (43a) into the groove (424) of the molded lower mold (42). Further, when the molten resin (M1) is cooled and solidified, and the resin rib (22) is integrated with the back surface of the foamed resin base material (21), the reinforcing fiber (a) mixed in the molten resin (M1). Thus, the resin rib (22) is suppressed from shrinkage during cooling and solidification, and the boundary surface (A) between the foamed resin base material (21) and the resin rib (22) is regulated to be substantially flat, while the resin rib ( 22) forming a resin rib (22) for forming;
The manufacturing method of the interior component for motor vehicles characterized by the above-mentioned.

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