JP2007030620A - Interior part for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an interior part for an automobile which totally or partially adopts a laminated structure consisting of a foam base material and a resin rib integrated on the back side of the foam base material and which can prevent an exfoliation failure between the resin rib and the foam base material. <P>SOLUTION: A door trim 10 consists of a door trim upper (the laminated structure) 20 and a door trim lower (a resin simple substance) 30. The door trim upper 20 is constituted by the laminated structure which is comprised of the foam base material 21 and the resin rib 22. The foam base material 21 is lightweight and has shape-retaining ability, and the resin rib 22 is integrated with the inner side of the foam base material 21. When a load is imposed on the product surface of the door trim upper 20, the exfoliation failure between the end part 22a of the resin rib 22 and the foam base material 21 is prevented as soon as possible because of the adoption of a stress-dispersion structure which disperses the stress direction in which an exfoliation stress acts between the foam base material 21 and the resin rib 22. <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. 13 and 14 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 upper molding 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 that serve as a passage for molten resin 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.

  Therefore, when the molding upper and lower molds 5 and 6 are in the mold open state, the skin 3 is set in the mold, and then the molding upper and lower molds 5 and 6 are clamped and then injected into the product cavity between both molds. By injecting and filling the molten resin M from the machine 7 through the manifold 6b and the gate 6c, 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. 15, 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 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. While providing a lightweight and inexpensive laminated structure, we found that it is possible to reliably prevent defective peeling between the resin rib and the foamed resin sheet by adding ingenuity to the terminal shape of the resin rib. 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 an automotive interior part that employs a laminated structure composed entirely of or in part, when a pressing load is applied to the surface of the laminated structure, the end portion of the resin rib and the foamed resin base material The stress distribution structure in which the stress direction of the peeling stress acting between them is dispersed is set at the end portion of the resin rib.

  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. In addition, the structure of the present invention can be applied to the entire structure of interior parts, and the structure of the present invention is applied to a part of automotive interior parts, for example, the door trim upper in the upper and lower split door trim composed of a door trim upper and a door trim lower. It can also be applied.

  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, Acrylonitrile / butadiene / styrene (ABS) resin 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 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. As this decorating material, a synthetic resin sheet such as a TPO sheet, a thermoplastic plastic urethane (TPU) sheet, a vinyl chloride sheet, or a fabric sheet such as a woven fabric, a nonwoven fabric, a knitted fabric, or a synthetic resin film, a foam, a net-like material, 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, the laminated structure is composed of the foamed resin base material and the resin rib integrated on the back surface of the foamed resin base material. When a pressing load is applied to the surface of the laminated structure body, the foamed resin base material is formed. In the present invention, the periphery of the pressing load portion is lifted upward and a peeling stress acts along the joint portion between the foamed resin base material and the resin rib. A stress distribution structure that can disperse the stress direction in which the peeling stress acts is employed.

  As this stress distribution structure, the rib depth is gradually shortened as it goes to the end, and an inclined edge portion whose inclination angle becomes smaller as it approaches the terminal is set, or the end portion of the resin rib Set up a stepped portion with reduced rib depth by thinning. The resin ribs extend in a crossing manner in the vertical and horizontal directions and diagonal directions, and are radially formed around the bosses for plate-like resin ribs, panel abutments, or brackets that are mainly used to enhance product rigidity. The present invention can be applied to extending resin ribs, resin ribs attached for the purpose of reinforcing rigidity around the clip mounting seat, and the like.

  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 by the molding die also includes a cooling process of the foamed resin sheet. The cooling process of the foamed resin sheet includes foaming in addition to cooling by mold clamping of the molding die. The resin sheet may be forcibly 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 stress dispersion structure is adopted at the end portion of the resin rib, and when a pressing load is applied from the product surface side of the laminated structure, the peeling stress applied to the end portion of the resin rib is dispersed. In addition, the separation between the foamed resin base material and the resin rib can be prevented as much as possible, and the rigidity of the product can be strengthened. Because it is set as an inclined edge where the inclination angle becomes smaller as it goes, or as a stepped part with reduced rib depth on the end side, the molten resin spreads quickly to the end portion of the resin rib, so a short shot Such a filling failure can be prevented in advance, and the adhesive strength with the foamed resin base material can be enhanced, so that the molding stability of the resin rib 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 interior part for automobiles according to the present invention, a stress distribution structure in which the direction of the peeling stress is dispersed is adopted at the end portion of the resin rib, and a pressing load is applied from the product surface side of the laminated structure. When added, since the stress load can be appropriately dispersed, it is possible to reliably prevent the peeling phenomenon that the terminal portion of the resin rib is peeled from the foamed resin base material, so that the rigidity of the laminated structure can be enhanced, In the stress distribution structure, since the rib depth is shallow, molten resin can flow quickly, molding defects such as short shots can be eliminated, and the bonding strength between the foamed resin substrate and the resin ribs can be strengthened. It has the effect of being excellent in properties.

  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. 12 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 structure 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 for the automobile, FIG. 4 is a cross-sectional view showing a configuration of a main part of the door trim upper in the door trim for the automobile, and FIGS. 5 and 6 are deformations of the resin rib in the door trim for the automobile Each sectional view showing an example, FIGS. 7 and 8 show a molding die used when molding the door trim for the automobile, FIG. 7 is an overall view of the molding die, and FIG. 8 is a door trim in the molding die. It is sectional drawing which shows an upper formation part. Further, FIGS. 9 to 12 show the respective steps of the manufacturing method of the automobile door trim, FIG. 7 is a preheating process of the foamed resin sheet, FIG. 8 is a process of setting the foamed resin sheet to the molding die, and FIGS. 12 is an explanatory view showing a door trim forming step.

  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 door trim 10 for an automobile is composed of an upper and lower divided body composed of 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. That is, the feature of the present invention is the boundary portion between the foamed resin base material 21 and the resin rib 22 in the door trim upper 20, particularly the shape of the terminal portion 22 a of the resin rib 22. That is, in this embodiment, the end portion 22a of the resin rib 22 integrated with the back surface of the foamed resin base material 21 is provided with the lightening portion a, and the rib depth gradually decreases toward the end. Edge portions 22b, 22c, and 22d are provided. Specifically, among the inclined edge portions 22b, 22c, and 22d, the first inclined edge portion 22b and the third inclined edge portion 22d extend substantially linearly, and the inclination angles thereof are θ1 and θ2, respectively. Show. The values of the inclination angles θ1 and θ2 are set to θ1: 30 to 60 ° and θ2: 5 to 30 °. Further, since the second inclined edge portion 22c is set as a curved edge portion with R of 3 to 30, the inclined edges 22b, 22c and 22d are smoothly continuous and have no conspicuous boundaries. is doing. Therefore, in FIG. 4, the force distribution form is shown only at the left end of the resin rib 22, but when a load F is applied from the product surface side of the door trim upper 20, the foamed resin base material 21 bends in the direction of arrow A, At that time, as shown in the drawing, the end portion 22a of the resin rib 22 particularly works so that the directions of the peeling stresses B1, B2, and B3 are dispersed in accordance with the shapes of the inclined edge portions 22b, 22c, and 22d. As a result, it is possible to reliably prevent the resin ribs 22 from peeling from the foamed resin base material 21. Moreover, about the structure of inclination edge part 22b, 22c, 22d, it is resin by employ | adopting the combination of only inclination edge part 22b, 22c, the combination of only inclination edge part 22b, 22d, and the combination of only inclination edge part 22c, 22d. The shape of the rib 22 can also be simplified.

  Further, since the rib depth of the resin rib 22 is reduced as it goes to the terminal portion 22a, the resin quickly spreads to the terminal portion 22a when the molten resin is filled in the mold. The adhesive strength with respect to the material 21 can be maintained well, and this is also a factor that prevents peeling. Thus, by adopting the stress distribution structure in the terminal portion 22a of the resin rib 22, it is possible to reliably prevent peeling between the resin rib 22 and the foamed resin base material 21, and to maintain the product rigidity firmly, Since the resin rib 22 can maintain good rigidity, the set length and number of ribs can be reduced, leading to cost reduction and weight reduction, and the molding stability of the resin rib 22 can also be improved. .

  Next, FIG. 5 and FIG. 6 show a modification of the resin rib 22, and as shown in FIG. 5, a stepped portion 22 e may be formed on the terminal portion 22 a of the resin rib 22 by the thinned portion a. . The rib height of the stepped portion 22e is preferably set to 2 / 3h or less, where h is the rib height of the general portion. Even when the stress distribution structure in which the step portion 22e is provided in this way, when a pressing load is applied to the product surface of the door trim upper 20, the peeling stress applied to the resin rib 22 particularly on the terminal portion 22a By being dispersed at the portion 22e, the peeling phenomenon of the resin rib 22 can be surely prevented, the molding stability can be improved, the number of resin ribs 22 and the set length can be reduced, and the cost and weight can be reduced. It has the same effect as the above-mentioned embodiment that it can contribute. Moreover, as shown in FIG. 6, the resin rib 22 can also be applied to the resin rib 22 formed radially on the outer periphery of a boss 24 such as a panel contacting boss or an accessory mounting boss. In other words, the stepped portion 22e having the thinned portion a provided in the terminal portion 22a of the resin rib 22 to reduce the rib depth can be applied to the resin rib 22 around the boss 24. Even in this case, it is possible to reliably prevent the peeling failure of the resin rib 22 that reinforces the boss 24 and to improve the moldability.

  Next, a method for molding the door trim 10 including the door trim upper 20 and the door trim lower 30 provided with the resin ribs 22 shown in FIG. 4 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.

  Furthermore, as shown in FIG. 8, 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 shape of the groove portion 424 is as follows. The groove depth of the terminal portion 424a is set to be shallow so that the resin rib 22 can realize the stress distribution structure at the terminal portion 22a. In addition, although not shown, the molding lower mold 42 may be provided with an air blow mechanism. As the air blow mechanism, a space between the compressed air blower and the air blow connected thereto communicates with an air chamber of the molding lower mold, and a refrigerant is introduced into the air chamber of the molding lower mold 42 by opening / closing an opening / closing valve provided between the air blows. 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. 9, 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. Then, as shown in FIG. 10, 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. 11, the raising / lowering cylinder 412 of the molding upper mold 41 is operated, the molding upper mold 41 is lowered by a predetermined stroke, and the molding upper and lower molds 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. 12, 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. In addition, as this molten resin M1, M2, the resin material which fillers, such as a talc, are mixed in an appropriate ratio with Sumitomo Nobrene BUE81E6 (the polypropylene made from Sumitomo Chemical, melt index = 80 g / 10min) 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.

  Then, when the molten resin M1 is injected and filled into the groove portion 424 of the molding lower mold 42, particularly, the end portion 424a of the groove portion 424 is set to have a very shallow groove depth, and therefore the molten resin M1 is formed on the end portion 424a. It is possible to avoid the filling failure such as a short shot in advance, and the molten resin M1 in a high temperature state where cooling does not start reaches the terminal portion 424a of the groove portion 424. The adhesive strength can be maintained firmly. Further, due to the shape of the end portion 424a of the groove portion 424, the end portion 22a of the resin rib 22 can realize a stress distribution structure, and stress is dispersed when a pressing load is applied to the product surface in the door trim upper 20. Therefore, it is possible to prevent the peeling failure at the terminal portion 22a of the resin rib 22 as much as possible.

  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 with the back surface as a structure of the door trim upper 20, and promotes weight reduction. At the same time, in particular, with respect to the end portion 22a of the resin rib 22 in the door trim upper 20, the inclined edge portions 22b, 22c, and 22d are set or the step portion 22e is set to reduce the rib depth of the resin rib 22. Therefore, when a pressing load is applied from the product surface side of the door trim upper 20, the terminal portion 22a of the resin rib 22 is not peeled off, and the moldability of the terminal portion 22a of the resin rib 22 is improved. Can the product rigidity be improved and the set length and number of resin ribs 22 can be reduced? , There is an advantage that is also effective in cost and weight.

  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 sectional drawing which shows the modification of the resin rib shown in FIG. It is sectional drawing which shows the modification of the resin rib 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 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. FIG. 14 is a sectional view taken along line XIV-XIV in FIG. 13. 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 vehicle door trim 20 Door trim upper 22 Resin rib 22a Terminal part 22b, 22c, 22d Inclined edge part 22e Step part 23 Decorating material 24 Boss 30 Door trim lower 40 Molding die 41 Molding upper mold 42 Molding lower mold 424 Groove part 424a Terminal part 43a, 43b Injection machine M1, M2 Molten resin a Meat removal part S Foamed resin sheet

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,
When a pressing load is applied to the surface of the laminated structure (20), the stress direction of the peeling stress acting between the terminal portion (22a) of the resin rib (22) and the foamed resin base material (21) is dispersed. The interior part for automobiles is characterized in that the stress distribution structure is set at the terminal portion (22a) of the resin rib (22).   As the stress distribution structure, the edge portion (22a) of the resin rib (22) has an inclined edge portion (22b, 22c, 22d) in which the rib depth becomes shorter as it goes to the end and the inclination angle (θ) becomes smaller. The interior part for automobiles according to claim 1, wherein The automotive interior component according to claim 1, wherein the stress distribution structure includes a step portion (22e) having a reduced rib depth at a terminal portion (22a) of the resin rib (22). .

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