JP2009154428A - Automobile interior component, and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automobile internal component in which a laminated structure composed of a foamed resin base material, and a surface skin and a resin rib integrated into the surface and rear face sides thereof is adopted at the whole or at a part thereof, and a method for manufacturing the component, where appearance performance is increased, and also, manufacturing cost is reduced. <P>SOLUTION: A door trim 20 is composed of: a door trim upper (laminated structure) 30; and a door trim lower (a resin simple substance article) 40. The door trim upper 30 is composed of a laminated structure of a foamed resin base material 31 light in weight and having shape retainability, a resin rib 32 integrated into the rear face of the resin base material 31 and a surface skin 33 beforehand molded into a required shape by an injection molding die 50 separately. The surface skin 33 is beforehand set in the molding die 60, integration between the foamed resin base material 31 and the surface skin 33 is performed upon the molding of the foamed resin base material 31, thus shrinkage to the surface of a product can be solved, the transfer of a drawn pattern can be performed with high precision, the degree of freedom in molding is increased, and also cost can be reduced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to automotive interior parts such as door trims, rear parcel shelves, floor trims, luggage trims, trunk trims, roof trims, rear side trims, and manufacturing methods thereof. The present invention relates to an automotive interior part that is excellent in performance and can be manufactured at low cost, and a method for manufacturing the same.

  13 and 14, the configuration of an automobile door trim that employs a laminated structure as a whole or a part thereof will be described. 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, a cushioning material such as polyethylene foam has been laminated on the back side of an elastomer sheet such as TPO (Thermoplastic Olefin) in consideration of environmental and recycling aspects. Laminated sheet materials tend to be used frequently.

  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 that serve as a passage of molten resin from the injection machine 7. Further, in order to properly maintain the pressing posture of the upper mold 5 that moves up and down, guide posts 6d are provided at the four corners of the lower mold 6 and the upper mold 5 is provided in correspondence with the guide posts 6d. A guide bush 5c is provided.

  Therefore, when the upper and lower molds 5 and 6 are in the mold open state, the skin 3 is set in the mold, and then the upper and lower molds 5 and 6 are clamped and then injected into the product cavity between the two 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. 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. This conventional example is disclosed in Patent Document 1.

  However, in this 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.

  Therefore, in order to solve these problems, the applicant has applied for a door trim that can be manufactured at a low cost at a low cost. As shown in FIGS. 16 and 17, the door trim 10 in the prior application example is molded into a desired curved surface shape, is lightweight and has a shape-retaining foamed resin base material 11, and a predetermined surface on the back surface of the foamed resin base material 11. The resin rib 12 is formed in a pattern shape, for example, a lattice shape in the vertical and horizontal directions, and a skin 13 laminated and integrated on the surface of the foamed resin base material 11. Then, the molding method of the door trim 10 will be described with reference to FIGS. 18 and 19. The molding die 14 is attached to the molding upper and lower molds 15 and 16 and the molding lower die 16 that can be mutually clamped and opened. The molded lower mold 16 is provided with a manifold 16a and a gate 16b that serve as a passage for the molten resin M supplied from the injector 17. . Further, a groove portion 16 c that matches the pattern shape of the resin rib 12 is formed in the mold surface of the molded lower mold 16.

  Then, the foamed resin sheet S, which is the material of the foamed resin base material 11, is heat-softened and then set in the molded upper and lower molds 15 and 16 in the mold open state as shown in FIG. Thereafter, as shown in FIG. 19, the molding upper and lower molds 15 and 16 are clamped to compress the foamed resin base material 11 into a desired curved surface shape, and the molten resin M is supplied from the injection machine 17 to the manifold 16a and the gate 16b. The resin ribs 12 having a predetermined pattern shape are integrated with the back surface of the foamed resin base material 11 by injection filling into the groove portion 16c of the molded lower mold 16 through. The skin 13 is laminated on one surface of the foamed resin sheet S in advance by a frame lamination method or the like. The configuration and the molding method of the lightweight door trim 10 which is the prior application example are described in detail in Patent Document 2.

JP 10-138268 A

JP 2005-119404 A

  As described above, for example, 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. The lightweight door trim 10 using the foamed resin base material 11 has the advantage that the product can be reduced in weight and desired rigidity can be ensured and manufactured at a relatively low cost. There was a problem with. That is, when the door trim 10 is molded, particularly when the resin rib 12 is injection-molded, shrinkage distortion occurs in the resin rib 12, which often causes a defect in appearance such that sink marks are formed on the product surface. Since the raw material sheet in the form of a sheet is laminated on the foamed resin sheet S and compression processing is performed by clamping the upper and lower molds 15 and 16, the expansion rate is limited, and it is difficult to form deep irregularities. There is a problem that the degree of freedom in modeling is restricted.

  Further, it is necessary to extrude or calender the raw sheet of the skin 13 into a sheet shape, and then to perform a fixed-size cut treatment, and then laminate the foamed resin sheet S, which leads to a high cost in a total sense. At the same time, in order to attach a drawing pattern to the surface of the skin 13, it is necessary to attach a vacuum mechanism to the molding upper die 15, and there is a problem that the cost of the mold is increased.

  The present invention has been made in view of such circumstances, and it is possible to reduce the weight of a product by using a foamed resin base material, to provide a desired rigidity, and to manufacture an automobile interior part that can be manufactured at a low cost. It is a manufacturing method that does not cause sink marks on the product surface and can be sharply shaped. It is an object of the present invention to provide an automobile interior part that can be simplified and a manufacturing method thereof.

  In order to solve the above problems, the present inventor has made a function as a core material by imparting shape retention to a foamed resin sheet that has been used as a skin as a result of earnest research. By placing resin ribs with excellent rigidity at locations where rigidity is required, i.e., peripheral parts of products, panels, or parts mounting locations, and parts where loads are applied, conventional resin core materials with a wide projected area can be obtained. Compared to providing interior parts for automobiles that are lighter and less expensive, in particular, the outer skin layered on the surface of the foamed resin base material is separately molded into the required shape by injection molding, while improving the appearance and cost. Focusing on the fact that it can be manufactured, the present invention has been completed.

  That is, the present invention relates to a foamed resin base material that is molded into a required shape, is lightweight and has shape retention, a resin rib having a predetermined pattern shape integrated with the back surface of the foamed resin base material, and a foamed resin base material In an interior part for an automobile that employs a laminated structure composed of a skin layered on the surface of the whole or a part thereof, the foamed resin base material in the laminated structure is made of a heat-softened foamed resin sheet. The upper and lower molds are set in a mold upper and lower molds and compressed into a desired curved shape by clamping the mold upper and lower molds, and the skin laminated on the surface of the foamed resin base material is previously molded by injection molding. It is molded into a curved shape and is integrated with the surface of the foamed resin base material when the foamed resin base material is molded.

  Here, the interior parts for automobiles can be applied to door trims, rear parcel shelves, floor trims, luggage trims, trunk 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. When it is removed from the mold, it has a rigidity (shape retention) enough to retain its shape. 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 substrate 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 1.0 to 10 mm.

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

  Furthermore, in order to enhance the appearance design of the product, as the skin integrated with the surface of the foamed resin base material, a skin molded in a required curved shape by an injection mold in advance is used. When setting the molding die, the molded skin is set on the molding upper die, and the skin may be integrated when molding the foamed resin base material. Thermoplastic olefin (hereinafter referred to as TPO) solid and TPO foam molded product can be used as the material of the skin. The thickness of TPO solid is 0.2 to 2.0 mm, and the thickness of TPO foam molded product. 0.3 to 5.0 mm can be used.

  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, after the skin is molded into the required shape by the injection molding method, it is integrated with the surface of the foamed resin base material when the foamed resin base material is molded. The drawn pattern can be easily transferred and is not affected by the shrinkage distortion after molding of the resin rib.

  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 the manufacturing method of interior parts for automobiles, in which the laminated structure composed of the resin ribs and the skin laminated on the surface of the foamed resin base material is employed in whole or in part, the method for producing the laminated structure is The injection molding process of injecting molten resin into the cavity of the injection mold and then cooling and solidifying to mold the skin into the required shape, and the skin molded into the required shape in the above process into the upper mold After setting on the mold surface, the foamed resin sheet, which is the material of the foamed resin base material, is heat-softened in the mold upper and lower molds in the mold open state, and then the material setting process and the mold upper and lower molds are clamped By foaming tree The sheet is drawn into the required shape to form the foamed resin base material into the required shape, the pre-formed skin is integrated on the surface side, and the molten resin is injected from the injection machine attached to the lower mold. It is characterized by comprising a foamed resin base material and a resin rib molding step in which a resin rib having a predetermined pattern shape is integrated with the back surface of the foamed resin base material by injection filling into the groove portion of the molded lower mold.

  Here, the molding die used for the manufacturing method of the interior parts for automobiles is an injection molding die for injection molding the skin into a product shape, and a molding for integrally molding the preformed skin, the foamed resin base material and the resin rib. Use both molds. The latter molding die includes a molding upper mold and a molding lower mold that can be clamped and opened, and an injection machine that is connected to the molding lower mold and supplies molten resin that is a material of the resin rib.

  And the manufacturing method of the interior component for motor vehicles concerning this invention is characterized by manufacturing a laminated structure in each process of following (1)-(3). That is, a skin molding process by injection molding, a process of setting a material for setting a skin molded by injection molding in a mold in an open state and a heat-softened foamed resin sheet, mold clamping and injection molding Thus, the process is roughly composed of three steps of a foamed resin base material and a resin rib molding step for molding the foamed resin base material and the resin rib.

  (1) Skin injection molding step: The molten resin is injected and filled into a cavity of an injection mold, and a skin having a desired shape is injection molded. As the material, TPO is used. In order to improve the appearance performance, it is desirable to transfer the drawn pattern from the injection mold side.

  (2) Skin and foamed resin sheet setting step: With the molding upper and lower molds opened, the upper and lower molds are set in the mold surface of the molding upper mold in advance, and the upper and lower molds are heated and softened. Insert the foamed resin sheet. At this time, an adhesive layer is laminated on one surface of the foamed resin sheet in consideration of adhesiveness to the skin.

  (3) Molding process of the foamed resin base material and the resin rib: When the setting of the skin material and the foamed resin sheet is completed, the molding upper die moves down by a predetermined stroke, and the foamed resin sheet is drawn by clamping the upper and lower molds. Then, the foamed resin base material is molded into a desired curved surface shape. At this time, the skin previously set on the molding upper die is integrated on the surface side of the foamed resin base material. Then, after cooling the foamed resin base material, the molten resin that is the material of the resin rib is injected and filled into the groove portion of the lower mold from the injection machine, and the resin rib having a predetermined pattern shape is integrated with the back surface side of the foamed resin base material. It becomes.

  Therefore, according to the method of the present invention, it is only necessary to mold a resin rib with a reduced projected area as compared with a conventional resin core material with a large projected area. Therefore, the material cost can be saved and the cooling time can be shortened as compared with the conventional resin core material.

  Furthermore, according to the method of the present invention, the skin integrated on the surface side of the foamed resin base material is molded in a required shape by an injection molding method in advance, so even if shrinkage distortion occurs in the resin rib, the skin is No shrinkage distortion is picked up, and there is no adverse appearance. And since the skin does not draw the sheet material, there is no restriction on the unfolding rate and the undercut shape is possible. be able to.

  In addition, according to the method of the present invention, the skin on the surface side of the foamed resin base material is molded into a required shape by an injection molding method. Compared to the conventional method of press molding by laminating with a foamed resin sheet, the total number of steps can be shortened, and the material cost and the mold cost can be reduced such that the vacuum porous mold can be eliminated.

  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, a resin rib integrated on the back surface of this foamed resin base material, and a skin layered and integrated on the surface of the foamed resin base material, the conventional heavy resin core material is abolished As a result, it is lightweight, low-cost, and is a porous material, so that it has the effect of being able to provide automotive interior parts with excellent sound absorption performance.

  Further, according to the automotive interior part and the manufacturing method thereof according to the present invention, the skin integrated on the surface side of the foamed resin base material is formed into a required shape by a separate injection mold before molding the foamed resin base material. Since the method of integrating the injection-molded product with the foamed resin base material is adopted, the skin is not adversely affected by the shrinkage distortion of the resin rib, and the product appearance is not sinked. In addition, since there is no restriction on the expansion rate, sharp shapes can be created, the degree of freedom of modeling can be dramatically improved, and transfer of drawn patterns etc. can be performed faithfully, greatly improving the appearance performance. Can do. Further, compared to the conventional method of forming the skin from a sheet material, the total man-hour can be reduced, the manufacturing cost can be suppressed, and the vacuum suction mechanism can be eliminated, so that the mold structure can be simplified.

  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. It should be noted that the gist of the present invention is as described in the 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. FIG. 4 is a cross-sectional view showing the structure of the door trim upper, FIG. 5 is an explanatory view showing the structure of an injection mold used for molding the skin of the door trim for the automobile, FIG. FIG. 7 is a plan view and a cross-sectional view showing a skin formed by an injection mold. FIG. 8 is an overall view showing a molding die used in the method for manufacturing the vehicle door trim, FIGS. 9 to 11 show each process in the method for manufacturing the vehicle door trim, FIG. 9 is a material setting step, FIG. 10 is an explanatory view showing the door trim upper molding process, FIG. 11 is an explanatory view showing the door trim lower molding process, and FIG. 12 is a sectional view showing a modification of the door trim upper in the automotive door trim according to the present invention.

  First, the configuration of a two-tone type automobile door trim 20 to which the present invention is applied will be described with reference to FIGS. The two-tone type automobile door trim 20 is composed of an upper and lower divided body of a door trim upper 30 made of a laminated structure and a door trim lower 40 made of a single resin. And as a functional component with which the door trim 20 is mounted | worn, the inside handle escutcheon 21 and the power window switch escutcheon 22 are attached to the door trim upper 30. FIG. Further, the door trim lower 40 has a door pocket opening 23, and a pocket back cover (made of a resin molded body) 24 is attached to the back side thereof as shown in FIG. A speaker grill 25 is provided on the front side of the door trim lower 40, or provided separately from the door trim lower 40.

  By the way, the automotive door trim 20 according to the present invention is characterized by the structure of the door trim upper 30 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 30 is molded into a desired curved surface shape and has a foamed resin base material 31 having a shape retaining property, and a resin rib integrated with the back surface side of the foamed resin base material 31. 32 and a skin 33 having a decorative function laminated and integrated on the surface side of the foamed resin base material 31.

  The foamed resin base material 31 has a shape after heat-softening the foamed resin sheet and heat-molded into a required shape, for example, cold press-molded 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. The foaming resin base material 31 has an expansion ratio of 2 to 10 times, and a thickness of 0.5 to 30 mm, particularly preferably 1.0 to 10 mm.

  Next, as shown in FIG. 3, the resin ribs 32 are set in a lattice pattern extending in the vertical and horizontal directions or in an oblique direction. And this resin rib 32 consists of a general-purpose synthetic resin molding which added reinforcement fibers, such as glass fiber and a natural fiber, As a synthetic resin which can be preferably used normally, polyethylene-type resin, polypropylene-type resin, polystyrene-type 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 20 shown in FIG. 1 to FIG. 3 includes the door trim upper 30 made of a laminated structure and the door trim lower 40 that is a single resin product, and has excellent appearance design due to the accent effect on the appearance. It has. Furthermore, the door trim upper 30 includes a foamed resin base material 31 having shape retention, a resin rib 32 laminated and integrated on the back surface of the foamed resin base material 31, and a skin 33 laminated on the surface of the foamed resin base material 31. Therefore, it is possible to eliminate the heavy resin core material that has been occupied over the entire surface of the product as in the prior art, and the lightweight foamed resin base material 31 is used, while the resin rib 32 has a bone shape. The parts to which the load is applied, for example, the parts excluding the clip mounting seat, the waist flange, the upper surface of the armrest portion, etc., have a thinning structure, and the weight of the product is 40% or more compared to the conventional example. The weight of the resin can be reduced, and the resin material can be saved significantly, which can contribute to cost reduction.

  The skin 33 is integrated on the surface side of the foamed resin base material 31 and is injection-molded into a required shape by an injection mold separate from the molding die for the foamed resin base material 31. As the material of the skin 33, TPO solid or TPO foamed product can be used. When TPO solid is used, the plate thickness is preferably 0.2 to 2.0 mm, and when TPO foamed product is used. The plate thickness is preferably 0.3 to 5.0 mm. Furthermore, if a drawing pattern is provided on the surface side of the skin 33, the appearance performance is further improved. As the material for the skin 33, synthetic rubber materials such as soft vinyl chloride resin and EPDM can be used in addition to TPO solid and TPO foam.

  Next, FIG. 4 is a cross-sectional view showing the configuration of the main part of the door trim upper 30. The door trim upper 30 is lightweight and has shape retention, and has a predetermined pattern on the back surface of the foamed resin base material 31 molded into a required shape. A resin rib 32 having a reduced projected area due to its shape is integrated, and a skin 33 having a decorating function is integrated on the surface of the foamed resin base material 31. And in the door trim 20 which concerns on this invention, in order to form the skin 33 on the surface of the foamed resin base material 31 by injection molding, there is no restriction | limiting of an expansion | deployment rate etc. compared with the conventional method of drawing-molding a sheet-like skin, The degree of freedom of modeling can be dramatically improved, and the drawn pattern can be easily transferred without a vacuum suction mechanism, and when the resin rib 32 is molded, shrinkage distortion after molding is a cause. It is possible to reliably prevent the occurrence of sink marks on the surface of the product, to improve the appearance performance, and to be advantageous in terms of man-hours as will be described later, resulting in a significant cost reduction.

  Here, the joint structure of the door trim upper 30 and the door trim lower 40 will be briefly described. As shown in FIG. 2, mounting bosses 41 are provided upright on the rear surface of the upper edge of the door trim lower 40 at appropriate pitch intervals. A mounting hole 31a is formed at the lower edge of the door trim upper 30 so as to correspond to the mounting boss 41. After the mounting boss 41 is inserted into the mounting hole 31a, the tip of the mounting boss 41 is subjected to ultrasonic caulking and thermal caulking. The door trim upper 30 and the door trim lower 40 can be easily integrated by caulking with a method such as the above. In this embodiment, the door trim upper 30 and the door trim lower 40 are integrated by caulking of the mounting boss 41 by ultrasonic welding. However, can they be integrated by fixing with screws or clips? Alternatively, simultaneous molding with a molding die is also possible.

Next, a method for manufacturing the above-described automobile door trim 20 will be described. Here, the manufacturing method of the door trim upper 30 in the automobile door trim 20 is as follows.
(1) Injection molding process of the skin 33,
(2) In-mold setting process of the skin 33 and the foamed resin sheet S,
(3) Molding process of the foamed resin base material 31 and the resin rib 32,
It consists of three processes.

  First, (1) the injection molding process of the skin 33 will be described with reference to FIGS. FIG. 5 shows a schematic configuration of an injection mold 50 used for molding the skin 33, and the injection mold 50 is generally composed of a cavity mold 51, a core mold 52, and an injection machine 53. After the movable cavity mold 51 is operated and the cavity mold 51 and the core mold 52 are clamped, the molten resin M1 such as TPO resin is injected from the injection machine 53 into the cavity defined between the two molds. Is injected and filled through the hot runner 54 and the gate 55 to form the skin 33 into a required shape. The skin 33 is formed into a desired curved surface shape as shown in the plan view shown in FIG. 6 and the cross-sectional view shown in FIG. 7. If desired, the outer skin 33 a may be integrated around the periphery. The appearance performance may be further enhanced by transferring a drawing pattern engraved on the mold surface of the cavity mold 51 to the product surface side.

  Next, (2) the in-mold setting process of the skin 33 and the foamed resin sheet S and (3) the molding process of the foamed resin base material 31 and the resin rib 32 will be described with reference to FIGS. FIG. 8 shows a schematic configuration of a molding die 60 for molding the foamed resin base material 31 and the resin rib 32. The molding die 60 includes a molding upper die 70 that can move up and down by a predetermined stroke, and a molding upper die 70. And a fixed molding lower mold 80 that is paired with the molding lower mold 80 and two injection machines 90 and 91 (referred to as a first injection machine 90 and a second injection machine 91) connected to the molding lower mold 80. Has been.

  More specifically, a cavity portion 71 that matches the product shape is set in the molding upper die 70, and is driven up and down by a predetermined stroke by an elevating cylinder 72 connected to the upper surface of the molding upper die 70. Guide bushes 73 are provided at the four corners of the molding upper die 70. On the other hand, the molding lower die 80 is provided with a core portion 81 corresponding to the cavity portion 71 of the molding upper die 70. The lower mold 80 is formed with a hot runner 82a and a gate 83a that serve as a resin passage for supplying the molten resin M2 for molding the resin rib 32 from the first injection machine 90, and door trim lower molding. As a resin passage for the molten resin M3 for use, the molten resin is injected and filled into the cavity C from the second injection machine 91 through the hot runner 82b and the gate 83b, and the door trim lower 40 is formed. In correspondence with the guide bush 73 of the molding upper mold 70, a guide post 84 is erected on the molding lower mold 80. The molding upper mold 70 is lowered and the molding upper and lower molds 70, 80 are clamped. When the guide post 84 is guided in the guide bush 73, the pressing posture of the upper mold 70 is properly maintained.

  Next, each step in the method for manufacturing the door trim 20 will be described with reference to FIGS. 9 to 11. As described above, the skin 33 in the door trim upper 30 is molded into a required shape using the injection mold 50, and the preformed skin 33 is formed in the upper half portion of the molding upper mold 70 as shown in FIG. Set on the mold surface using a holding force (not shown) by a set pin or a vacuum suction mechanism. At the same time, the foamed resin sheet S is heat-softened by the heater device 100, and the heat-softened foamed resin sheet S is put into the upper and lower molds 70 and 80 in the mold open state. In this embodiment, the foamed resin sheet S that is the material of the foamed resin base material 31 is a polypropylene foamed sheet (manufactured by Sumika Plustech, trade name: Sumiceller foamed PP sheet, foaming magnification = 3 times, thickness 3 mm). in use. Further, an adhesive layer 34 such as hot melt is laminated on the surface of the foamed resin sheet S facing the skin 33 so as to function as an adhesive medium.

  Then, when the setting work of the outer skin 33 and the foamed resin sheet S is completed, as shown in FIG. 10, the upper mold 70 is lowered by a predetermined stroke by driving the lifting cylinder 72, and the upper and lower molds 70, 80 are clamped. Then, the foamed resin base 31 is formed into a desired curved shape by the foamed resin sheet S following the cavity shape. Next, when the foamed resin base material 31 is molded, the pre-molded skin 33 and the foamed resin base material 31 are integrated by the adhesive force of the pressure-sensitive adhesive layer 34 serving as an adhesive medium, and the first injection machine 90 to a molten resin M2, for example, Sumitomo Noblen BUE81E6 (manufactured by Sumitomo Chemical Co., Ltd., melt index = 65 g / 10 min) is used to melt the molten resin into the groove 85 of the lower mold 80 through the hot runner 82a and the gate 83a. By injecting and filling the resin M2, the resin ribs 32 having a predetermined pattern shape can be integrated with the back surface of the foamed resin base material 31. The injection filling timing of the molten resin M2 may be performed simultaneously with the mold clamping of the upper and lower molds 70 and 80, or may be performed after setting the time lag after the mold upper and lower molds 70 and 80 are clamped. good. The above is the molding process of the door trim upper 30.

  Next, as shown in FIG. 11, the molten resin M3 as the material of the door trim lower 40 from the second injector 91 is injected and filled into the cavity C through the hot runner 82b and the gate 83b, so that the door trim lower 40 is desired. It is injection molded into a curved shape. As the molten resin M3, a resin material of the same system different in color from the resin rib 32, for example, Sumitomo Nobrene BUE81E6 (manufactured by Sumitomo Chemical Co., Ltd., melt index = 65 g / 10 min) is used. The above is the molding process of the door trim lower 40.

  Therefore, in the method of the present invention, the skin 33 in the door trim upper 30 is molded using the injection mold 50 and the molding process of the door trim upper 30 and the door trim lower 40 is performed using the mold 60. However, only the door trim upper 30 may be molded by the molding die 60 and may be integrally joined to the door trim lower 40 molded by a separate die by ultrasonic processing or the like.

  In addition, as shown in FIG. 12, a cushion layer 35 that imparts a soft feeling to one surface of the foamed resin base material 31 may be integrated. The cushion layer 35 is preferably a foamed resin molded body such as polypropylene foam or polyethylene foam. Furthermore, by providing the cushion layer 35 on one surface of the foamed resin base material 31, the conditions during the heat processing by the heater device 100 can be stabilized. That is, it is possible to reduce sagging due to drawdown during heating due to an increase in tensile strength, to stabilize the plate thickness, and to reduce the expansion rate.

  In the embodiment described above, the structure of the present invention is applied to the door trim upper 30 of the two-tone type automobile door trim 20 and the method of the present invention is applied to the method of manufacturing the door trim upper 30. The structure and method of the present invention can be applied to all interior trims such as interior parts such as rear parcel shelves, floor trims, luggage trims, trunk trims, roof trims, rear side trims and the like.

It is a front view showing an example in which the present invention is applied to a two-tone type automobile door trim. It is the II-II sectional view taken on the line in FIG. It is a front view which shows the state which removed the foamed resin base material of the door trim upper in the door trim shown in FIG. It is sectional drawing which shows the structure of the door trim upper shown in FIG. It is explanatory drawing which shows schematic structure of the injection mold which shape | molds the skin of the door trim upper in the door trim to which this invention is applied. It is a front view which shows the outer skin of the door trim upper in the door trim to which this invention is applied. It is sectional drawing which shows the outer skin of the door trim upper in the door trim to which this invention is applied. It is explanatory drawing which shows schematic structure of the molding die used for the manufacturing method of the door trim for motor vehicles to which this invention is applied. It is explanatory drawing which shows the setting process of the raw material in the shaping die in the manufacturing method of the door trim for motor vehicles to which this invention is applied. It is explanatory drawing which shows the formation process of the door trim upper in the manufacturing method of the door trim for motor vehicles to which this invention is applied. It is explanatory drawing which shows the formation process of the door trim lower in the manufacturing method of the door trim for motor vehicles which applied this invention. It is sectional drawing which shows the modification of the door trim upper in the door trim to which this invention is applied. It is a front view which shows the conventional door trim for motor vehicles. It is the XIV-XVI sectional view taken on the line in FIG. It is explanatory drawing of the shaping die used when shape | molding the conventional door trim. It is a front view which shows the lightweight door trim which is an example of a prior application. It is the XVII-XVII sectional view taken on the line in FIG. It is explanatory drawing which shows the setting process of the raw material in the manufacturing method of the lightweight door trim which is a prior application example. It is explanatory drawing which shows the formation process of the foamed resin base material and the resin rib in the manufacturing method of the lightweight door trim which is a prior application example.

Explanation of symbols

20 Two-tone type automobile door trim 30 Door trim upper (laminated structure)
31 Foamed resin base material 32 Resin ribs 33 Skin 34 Adhesive layer 35 Cushion layer 40 Door trim lower (single resin)
DESCRIPTION OF SYMBOLS 50 Injection mold 60 Mold 70 Mold upper mold 71 Cavity part 72 Cylinder 73 Guide bush 80 Molding lower mold 81 Core part 82a, 82b Hot runner 83a, 83b Gate 84 Guide post 85 Groove part 90 1st injection machine 91 1st injection machine Injection machine 2 100 Heater device S Foamed resin sheet M1 Molten resin (for skin molding)
M2 molten resin (for resin rib molding)
M3 molten resin (for door trim lower molding)

Claims (2)

A foamed resin base material (31) which is molded into a required shape and is lightweight and has shape retention, a resin rib (32) having a predetermined pattern shape integrated with the back surface of the foamed resin base material (31), and foaming In an automotive interior part (20) formed by adopting a laminated structure (30) composed of a skin (33) laminated on the surface of a resin substrate (31) as a whole or a part thereof,
In the foamed resin base material (31) in the laminated structure (30), a heat-softened foamed resin sheet (S) is set in a molded upper / lower mold (70, 80), and the molded upper / lower mold (70, 80). ) Is clamped into a desired curved surface shape, and the skin (33) laminated on the surface of the foamed resin base material (31) is previously molded into a desired curved shape by injection molding. An automobile interior part characterized by being integrated with the surface of the foamed resin base material (31) when the foamed resin base material (31) is molded. A foamed resin base material (31) which is molded into a required shape and is lightweight and has shape retention, a resin rib (32) having a predetermined pattern shape integrated with the back surface of the foamed resin base material (31), and foaming In the manufacturing method of the automotive interior part (20) formed by adopting the laminated structure (30) composed of the skin (33) laminated on the surface of the resin base material (31) in whole or in part,
The laminated structure (30) is manufactured by injecting and filling molten resin (M1) into a cavity of an injection mold (50), and then cooling and solidifying the outer skin (33) into a required shape ( 33) an injection molding process;
After setting the skin (33) molded into the required shape in the above process on the mold surface of the molding upper mold (70), the foamed resin substrate (31) is placed in the mold upper and lower molds (70, 80) in the mold open state. ) The foaming resin sheet (S) that is the material of the material is set after the heat softening treatment,
By molding the upper and lower molds (70, 80), the foamed resin sheet (S) is drawn into the required shape to form the foamed resin base material (31) into the required shape, and pre-molded on the surface side. The formed skin (33) is integrated, and molten resin (M2) is injected and filled into the groove (85) of the molded lower mold (80) from the injection machine (90) attached to the molded lower mold (80). A molding step of the foamed resin base material (31) and the resin rib (32) for integrating the resin rib (32) having a predetermined pattern shape on the back surface of the foamed resin base material (31),
A method for producing an interior part for an automobile, comprising:

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