JP2008173894A - Car trim part and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate the leak of a resin at the time of molding of a resin rib in a car trim part which employs a laminated structure, which is composed of a foamed resin base material and the resin rib integrated with the back side thereof, wholly or partially. <P>SOLUTION: A door trim 10 is constituted of a door trim upper (laminated structure) 20 and a door trim lower (resin single product) 30. The door trim upper 20 is constituted of a laminated structure composed of a lightweight foamed resin base material 21 having shape retention and the resin rib 22 having a predetermined pattern shape integrated with the inner surface side thereof and a stepped attaching part 24, of which the thickness d2 is larger than the thickness d1 of a general part, is formed to the foamed resin base material 21 in the joining part of the resin rib 22. When the resin rib 22 is molded by injecting and charging a molten resin M1 in the groove part 424 of a lower mold 42, both corner parts of the corner part of the groove part 424 and the corner part of a recessed part 427 act as seal parts A and B to eliminate the leak of the resin. <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. 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 for molding the door trim 1 is connected to a molding upper die 5 capable of moving up and down by a predetermined stroke, a molding lower die 6 on the fixed side 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. The upper mold 5 that moves up and down is provided with guide posts 6d at the four corners of the lower mold 6 in order to maintain the press posture properly. The upper mold 5 is formed in correspondence with the guide posts 6d. A guide 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. 14, 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 lightweight and inexpensive laminated structure, a sealing pressure is applied between the resin rib molding groove portion provided in the molding die and the foamed resin base material. Focusing on the fact that resin leakage can be prevented by setting a seal portion that can avoid resin leakage, the present invention has been completed.

  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, in which the foamed resin base material in the laminated structure is drawn between the upper and lower molds, and the resin rib located on the inner surface thereof is Molded resin is injected and filled into the groove of the mold, and a seal part that suppresses leakage of the molten resin is formed on the mold surface of the molded lower mold. Is characterized in that a stepped attachment portion set to a thickness larger than the thickness of the general portion is formed.

  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.

  And in order to improve an external appearance design property, the decorating material may be laminated | stacked and integrated on the surface of the foamed resin base material. The decorating material is not limited, but is composed of a top layer that enhances the surface appearance and a two-layer laminated sheet material that provides cushioning performance. The top layer can be a TPO sheet or a thermoplastic urethane. Synthetic resin sheets such as (TPU) sheets and PVC sheets, or fabric sheets such as woven fabrics, non-woven fabrics, and knitted fabrics can be used. As cushion layers, cushion layers such as polypropylene foam, polyethylene foam, polyurethane foam, etc. Can be used.

  On the other hand, the thermoplastic resin material used as the resin rib can be appropriately selected from a wide range of thermoplastic resins. Usually, those that can be preferably used include polyethylene resins, polypropylene resins, polystyrene resins, 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.

  According to the automotive interior part of the present invention, since the resin rib is laminated and integrated on the back side of the foamed resin base material having shape retention, the conventional resin is laminated. The core material can be abolished. Therefore, by eliminating the conventional resin core material having a very large projected area, the weight of the product can be reduced and the resin material can be saved, so that the material cost can be reduced at the same time. In addition, the porous sound absorption function of the foam resin base material provides interior parts with excellent sound absorption performance. When polyolefin resin is used as the material for the foam 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, according to the interior part for automobiles according to the present invention, the foamed resin base material at the portion to be joined to the resin rib has a stepped attachment portion thicker than the thickness of the general portion. By applying sealing pressure to the foamed resin base material at the corner of the groove and the corner of the stepped mounting portion, the molten resin does not leak to the outside, and the product surface irregularities that cause resin leakage can be eliminated At the same time, molding defects such as short shots can be prevented.

  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 is formed by molding a foamed resin sheet that has been heat-softened in a mold open state. After setting in the upper and lower molds, the molded upper and lower molds are clamped to form the foamed resin base material in the required shape along the cavity shape formed between the molded upper and lower molds. When the foamed resin base material is molded to mold the foamed resin base material and the upper and lower molds are clamped, and the molten resin is injected and filled into the groove of the lower mold from the injection machine, Groove First-stage sealing is performed with the foamed resin base material using the inner part as the first sealing part, and the corner part in the concave portion of the molded lower mold corresponding to the stepped mounting part of the foamed resin base material is second sealed. A resin rib molding step for integrating the resin rib on the back surface of the foamed resin base material while avoiding leakage of the molten resin to the outside by performing a second-stage seal with the foamed resin base material as a part It is characterized by comprising.

  Here, the molding die used for the molding method of interior parts for automobiles is connected to 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 a molding lower mold. The molten resin supplied from the injection machine is inserted into a groove formed in 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. Supplied. In addition, if desired, a vacuum suction mechanism may be provided on the molding upper die, and when the foamed resin base material is drawn, a vacuum suction force is applied from the molding upper die to improve the shape retention of the product shape. It is advantageous for transferring a drawn pattern or the like. On the other hand, an air blow mechanism may be attached to the lower mold, and the air blow mechanism can shorten the cooling cycle by blowing cooling air when molding the foamed resin base material.

  Furthermore, the molding die used in the method of the present invention has a shallow bottom recess formed on both sides of the groove for molding the resin rib as the shape of the molding lower mold. By setting it larger than the clearance, when the resin rib is formed on the back surface of the foamed resin base material, a sealing action is obtained that prevents the resin from leaking to the outside at each corner portion of the groove portion and the stepped attachment portion.

  Therefore, according to the method of 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. Therefore, by setting the injection pressure lower than in the conventional case, the load on the molding upper mold is reduced. The amount of resin can be reduced, the amount of resin can be reduced, the material cost can be saved, the cooling time is shorter than that of the conventional resin core material, and the molding cycle can be greatly shortened.

  Furthermore, according to the method of the present invention, since the mold clearance of the molding upper and lower molds is set larger than the mold clearance of the general part on both sides of the groove portion of the molded lower mold, the foamed resin base material is drawn by molding with the molded upper and lower molds. If the molten resin is injected and filled into the groove portion of the molded lower mold while being compressed and held, the sealing pressure acts between the foam resin base material at the corner portion of the groove portion and the corner portion of the stepped mounting portion. And it can prevent as much as possible that a molten resin leaks outside by this sealing pressure. Therefore, there is no material loss, there is no molding defect such as a short shot, and the appearance defect of the product surface caused by resin leakage can be prevented in advance.

  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 method for manufacturing the same according to the present invention, the foamed resin sheet is drawn by clamping the upper and lower molds to form the foamed resin base material into the required shape. The molten resin is injected and filled into the groove portion of the molding lower mold located on the back surface of the base material, and the molten resin is integrated, and when the molten resin is injected and filled into the groove portion, the molding lower mold and the foam resin Since the seal part is set at each corner part of the groove part and the stepped attachment part between the base material, there is no molding failure such as resin leakage or short shot at the time of resin rib molding, and the appearance caused by resin leakage In addition to effectively eliminating defects, molding defects such as short shots can be reliably prevented, and appearance performance and moldability can be improved.

  Hereinafter, preferred embodiments of an automobile interior part and a manufacturing method thereof according to the present invention will be described by exemplifying an automobile door trim and a manufacturing method thereof. 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.

  FIGS. 1 to 11 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 longitudinal sectional view showing the configuration of the automobile door trim, and FIG. FIG. 4 is a front view showing a resin rib and a door trim lower of a door trim upper in the automobile door trim, and FIG. 4 is a cross-sectional view showing a main part configuration of the door trim upper in the automobile door trim. 5 and 6 show a molding die used in the manufacturing method of the door trim for the automobile, FIG. 5 is an explanatory view showing the entire configuration of the molding die, and FIG. 6 is for resin rib molding in the molding die. It is explanatory drawing which shows the structure of the groove part vicinity. 7 to 11 show the respective steps in the manufacturing method of the automobile door trim, FIG. 7 is an explanatory view showing the preheating process of the foamed resin sheet, and FIG. 8 is an explanatory view showing the setting process of the foamed resin sheet. 9 is an explanatory diagram showing the molding process of the foamed resin base material, FIG. 10 is an explanatory diagram showing the molding process of the resin rib, and FIG. 11 is an explanatory diagram showing the operation of the molding die at the time of molding the resin rib shown in FIG. .

  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. The decorative 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 the 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.

  Next, FIG. 4 is a cross-sectional view showing the main configuration of the door trim upper 20, and the door trim upper 20 has a predetermined pattern on the back surface of the foamed resin base material 21 that is lightweight and has shape retention. Shaped resin ribs 22 are integrated, and a decorative material 23 having cushioning properties is laminated on the surface of the foamed resin base material 21.

  In particular, the door trim upper 20 in the automotive door trim 10 according to the present invention is free from resin leakage or short shots when the resin rib 22 is molded, improves moldability, and has poor appearance such as product surface irregularities caused by resin leakage. Can be drastically solved. Therefore, in order to ensure the sealing property of the molten resin for molding the resin rib 22, the resin rib 22 joining portion in the foamed resin base material 21 is provided with a stepped mounting portion 24 in order to provide a sealing function to the mold. As compared with the thickness d1 of the general part of the foamed resin base material 21, the thickness d2 of the foamed resin base material 21 at the set position of the resin rib 22 is set larger. Although the operation will be described later, by adopting such a configuration, there is no resin leakage at the time of injection molding of the resin rib 22, the smoothness of the product appearance is emphasized, and there is no molding defect such as a short shot. It is also advantageous for resource saving.

  Next, the configuration of the molding die 40 will be described with reference to FIGS. First, as shown in FIG. 5, the molding die 40 is connected to 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. And two injection machines 43a and 43b. 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. Guide bushes 413 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. The injection machine 43a passes through the resin passages of the manifolds 422a and 422b and gates 423a and 423b. , 43b is supplied to the upper surface of the core portion 421. In order to form the resin rib 22, a groove portion 424 to which the molten resin M <b> 1 is supplied is formed on the upper surface of the core portion 421. In order to form the door trim lower 30, a predetermined gap is formed between the upper and lower molds 41 and 42. A clearance cavity 425 is set. In addition, guide posts 426 serving as a guide mechanism protrude from the four corners of the molding lower die 42. The guide posts 426 guide the molding upper die 41 when the molding upper and lower dies 41, 42 are clamped. By guiding the guide post 426 into the bush 413, the pressing posture of the molding upper die 41 can be properly maintained.

  By the way, as shown in FIG. 6, the molding die 40 used in the method of the present invention has a stepped mounting portion 24 on the foamed resin base material 21 on both sides of the groove portion 424 drilled in the molding lower die 42. A recess 427 having a shallow bottom shape is formed so as to be formed. In two places, a corner portion A of the groove portion 424 and a corner portion B of the recess portion 427, both corner portions A and B function as seal portions, and a molten resin When M1 is injected and filled, it is sealed at this portion to prevent the molten resin from seeping out to the outside as much as possible. Hereafter, each process of this invention method is demonstrated.

  First, as shown in FIG. 7, the heater device 50 laminates the decorative material 23 on one surface of the foamed resin sheet S and heat-softens it to a predetermined temperature. 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.

  Next, as shown in FIG. 8, the heat-softened foamed resin sheet S (the decorative material 23 is laminated) of the cavity portion 411 of the molding upper mold 41 and the molding lower mold 42 at the location corresponding to the door trim upper 20. Set in the upper half of the cavity defined by the core part 421. If desired, the foamed resin sheet S and the decorating material 23 may be set separately in the molding die 40. After the foamed resin sheet S is set, the lifting 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, and the foamed resin sheet S is shaped along a desired mold surface shape (see FIG. 9).

  Further, the injection molding of the resin rib 22 and the door trim lower 30 is performed simultaneously with the molding of the foamed resin base material 21 or after the molding. That is, when the molded upper and lower molds 41 and 42 are in the clamped state, the molten resin M1 is injected and filled into the groove 424 from the first injection machine 43a through the manifold 422a and the gate 423a. In the present embodiment, 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 to simultaneously mold the door trim lower 30. As the molten resins M1 and M2, Sumitomo Nobrene BUE81E6 (polypropylene manufactured by Sumitomo Chemical Co., Ltd., melt index = 80 g / 10 min) is used. Moreover, talc is mixed in the molten resins M1 and M2 at an appropriate ratio.

  In the method of the present invention, as is apparent from FIG. 11, when the molten resin M1 is injected and filled into the groove portion 424, concave portions 427 are formed on both sides of the groove portion 424 of the molding lower die 42, Since the foamed resin base material 21 is molded into a required shape by the upper and lower molds 41 and 42 and is held in a compressed state, it corresponds to the first seal portion A corresponding to the corner portion of the groove portion 424 and the corner portion of the concave portion 427. The second sealing portion B is reliably sealed and resin leakage is avoided. Therefore, according to the method of the present invention, since the resin leakage can be blocked by the two seal portions A and B, the resin rib 22 can prevent the short shot as much as possible and can improve the moldability. Further, it is possible to reliably prevent the appearance defect that the surface of the product is uneven due to resin leakage, and to improve the molding performance and appearance performance.

  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. Further, as a method of forming the door trim lower 30, a method of injecting and filling the molten resins M1 and M2 almost simultaneously as in the embodiment may be adopted. However, a molten resin M2 in the door trim lower 30 is set by setting a time lag. The injection filling time may be delayed from the injection filling time of the molten resin M1.

1 is a front view showing an embodiment in which an automotive interior part according to the present invention is applied to a two-tone type automotive door trim. 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 after removing the foamed resin base material of the door trim upper in the door trim for motor vehicles shown in FIG. It is sectional drawing which shows the structure of the door trim upper in the door trim for motor vehicles shown in FIG. FIG. 2 is an overall view showing a configuration of a molding die used when molding the door trim shown in FIG. 1. It is principal part sectional drawing which shows the structure of the groove part periphery in the molding 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 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 supply process of the molten resin in the manufacturing method of the door trim shown in FIG. It is an enlarged view of the resin rib equivalent location shown in FIG. It is a front view which shows the conventional door trim for motor vehicles. FIG. 13 is a sectional view taken along line XIII-XIII in FIG. 12. It is explanatory drawing 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 21 Foamed resin base material 22 Resin rib 23 Decorating material 23a Top layer 23b Cushion layer 24 Step mounting part 30 Door trim lower 40 Molding die 41 Molding upper mold 413 Guide bush 42 Molding lower Mold 426 Guide post 427 Recess 43a, 43b Injection machine 50 Heater device S Foam resin sheet M1, M2 Molten resin A, B Seal part

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 foamed resin base material (21) in the laminated structure (20) is drawn between the molded upper and lower molds (41, 42), and the resin rib (22) located on the inner surface thereof is formed by the molded lower mold (42). ) Is molded by injecting and filling molten resin (M1) into the groove portion (424), and seal portions (A, B) that suppress leakage of the molten resin (M1) are formed on the mold surface of the molded lower die (42). Therefore, the foamed resin base material (21) at the portion to be joined to the resin rib (22) has a stepped mounting portion (24) set to a thickness (d2) larger than the thickness (d1) of the general portion. An automotive interior part characterized by being formed. 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,
In the laminated structure (20), the heat-softened foamed resin sheet (S) is set in the molded upper and lower molds (41, 42) in the mold open state, and then the molded upper and lower molds (41, 42) are molded. When the foamed resin base material (21) is molded into the required shape along the cavity shape formed between the molded upper and lower molds (41, 42) by tightening, the step mounting is performed at the corresponding portion of the resin rib (22). Forming the foamed resin base material (21) so as to include the part (24),
When the mold upper and lower molds (41, 42) are clamped and the molten resin (M1) is injected and filled into the groove (424) of the molded lower mold (42) from the injection machine (43a), the corner of the groove (424) The first-stage seal is performed between the first seal portion (A) and the foamed resin base material (21), and the molded part corresponding to the stepped attachment portion (24) of the foam resin base material (21) By performing the second-stage sealing with the foamed resin base material (21) using the corner portion in the concave portion (427) of the mold (42) as the second seal portion (B), the outside of the molten resin (M1) A resin rib (22) molding step for integrating the resin rib (22) on the back surface of the foamed resin base material (21) while avoiding leakage to
A method for producing an interior part for an automobile, comprising:

Images