JP2008173896A - Automotive interior trim and its manufacturing process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance an appearance performance and also reduce a manufacturing cost in an automotive interior trim and its manufacturing process of wholly or partially employing a laminated structure including a foamed resin substrate, and a top layer and a resin rib integrated on its front and rear surface side respectively. <P>SOLUTION: A door trim 20 comprises a door trim upper (laminated structure) 30 and a door trim lower (resin simple substance article) 40. The door trim upper 30 is formed by the laminated structure comprising the foamed resin substrate 31 having a light weight and shape retention, the resin rib 32 integrated on its rear surface, and the top layer 33 injection-molded on the surface side of the foamed resin substrate 31; and the top layer 33 is molded by injection molding, thus enabling a molding degree of freedom to be enhanced, a surface shrinkage hole caused by contraction distortion of the resin rib 32 to be prevented and transfer of a tie-dye pattern to be accurately carried out. <P>COPYRIGHT: (C)2008,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.

  For example, the configuration of an automotive door trim that uses part or all of the laminated structure 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, 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 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. In FIG. 17, 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. 18 and 19, 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 is provided on the back surface of the foamed resin base material 11. It is comprised from the pattern shape, for example, the resin rib 12 formed in the grid | lattice form of the vertical / horizontal direction, and the decorating material 13 laminated | stacked and integrated on the surface of the foamed resin base material 11. FIG. The molding method of the door trim 10 will be described with reference to FIGS. 20 and 21. As shown in FIG. 20, the molding die 14 includes molding upper and lower molds 15 and 16 that can be clamped and opened with each other. The molding lower mold 16 includes an injection machine 17 serving as a molten resin supply mechanism. The molding lower mold 16 includes a manifold 16a serving as a passage for the molten resin M supplied from the injection machine 17. A gate 16b is provided. 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 that is the material of the foamed resin base material 11 is heated and softened, and then set in the molded upper and lower molds 15 and 16 in the mold open state. Thereafter, as shown in FIG. 21, the 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. Further, the decorating material 13 is laminated in advance on one surface of the foamed resin sheet S of the foamed resin base material 11 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, so that the appearance defect that sink marks are formed on the product surface frequently occurs and the decorative material is used. No. 13, since a sheet-like raw fabric sheet is laminated on the foamed resin sheet S, and compression processing is performed by clamping the molded upper and lower molds 15 and 16, the expansion rate is limited and it is difficult to form deep irregularities. For example, there is a problem in that there is a restriction on modeling.

  Further, it is necessary to extrude or calender-mold the original sheet of the decorating material 13 into a sheet, and then apply a fixed-size cut treatment, and then laminate the foamed resin sheet S, which increases the cost in the total sense. In addition, in order to attach a drawing pattern to the surface of the decorating material 13, it is necessary to attach a vacuum mechanism to the molding upper die 15, resulting in 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 it is possible to sharpen the shape, etc., and it can dramatically improve the appearance of the appearance, and it can be manufactured at low cost in terms of cost, It is another object of the present invention to provide an automobile interior part that can simplify the mold structure and a manufacturing method thereof.

  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 as a result of intensive studies. Conventional resin core material with a wide projected area by placing resin ribs with excellent rigidity at locations where rigidity is required, that is, peripheral parts of products, panels, parts mounting locations, and parts where load is applied. Compared to the above, it provides automobile interior parts that are lighter and less expensive, and in particular, a cavity for forming a top layer integrally with a molding die for molding a foamed resin base material and resin rib is set. By injecting and filling molten resin into this cavity, it is possible to sharpen the shape without being adversely affected by the heat from the resin ribs, improving the appearance of the product. Noting that can reduce the molding steps of the top layer, thereby completing the present invention.

  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 automotive interior part that employs a laminated structure consisting of a top layer laminated on the surface of the whole or a part thereof, the foamed resin base material in the laminated structure is a foamed resin sheet that has been heat-softened Is set in a molded upper and lower mold, and the molded upper and lower molds are compressed into a desired curved surface shape by clamping the molded upper and lower mold, and a resin rib having a predetermined pattern shape that reinforces rigidity on the back side of the foamed resin base material However, the top layer which improves a buffer property and the designability is respectively laminated and integrated on the surface side of the foamed resin base material.

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

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

  As the foamed resin sheet, a material obtained by adding a foaming agent to a thermoplastic resin is used. The thermoplastic resin may be one type of thermoplastic resin or two or more types of thermoplastic resins. Preferably, polyethylene resin, polypropylene resin, polystyrene resin, polyethylene terephthalate resin, polyvinyl alcohol resin, vinyl chloride resin, polyamide resin, polyacetal resin, polycarbonate resin, ionomer resin, acrylonitrile / butadiene / Styrene (ABS) resin or the like can be used. As the foaming agent, an organic foaming agent such as an azo compound, a sulfohydrazide compound, a nitroso compound or an azide compound, or an inorganic foaming agent such as sodium bicarbonate can be used. The foamed resin base material obtained by molding the foamed resin sheet into a required shape after heat softening treatment preferably has a foaming ratio of 2 to 10 times in consideration of the balance between the weight and strength of the product. The cell diameter of the foamed resin base material at that time is preferably in the range of 0.1 μm to 2.0 mm, and the thickness is 0.5 to 30 mm, preferably 1 to 10 mm.

  On the other hand, the thermoplastic resin material used as the resin rib can be appropriately selected from a wide range of thermoplastic resins. Usually, those that can be preferably used include polyethylene resins, polypropylene resins, polystyrene resins, polyethylene terephthalate resins, polyvinyl alcohol resins, vinyl chloride resins, polyamide resins, polyacetal resins, polycarbonate resins, ionomer resins, Examples include acrylonitrile / butadiene / styrene (ABS) resin. Moreover, you may mix various fillers in these thermoplastic resins. Examples of the filler that can be used include inorganic fibers such as glass fiber and carbon fiber, and inorganic particles such as talc, clay, silica, and calcium carbonate. Moreover, various additives, such as antioxidant, a ultraviolet absorber, a coloring agent, a flame retardant, and a low shrinkage agent, may be mix | blended.

  And in order to improve the appearance design, as a top layer laminated and integrated on the surface of the foamed resin base material, the foamed resin base material is pressed instead of press-integrating the sheet-like material together with the foamed resin sheet. After molding, a cavity with a predetermined thickness is formed between the surface of the foamed resin base material and the molding die, and a top layer is formed on the surface of the foamed resin base material by injection-filling the thermoplastic resin material into the cavity. Is integrally molded. As a material for the top layer, a soft resin material such as a thermoplastic elastomer (for example, a thermoplastic plastic olefin), a vinyl chloride resin, or a rubber-based material is preferable.

  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, since the top layer is formed by injection molding on the surface of the foamed resin base material after molding the foamed resin base material, there are no restrictions on molding, such as restrictions on the development rate, and easy to transfer the drawn pattern. It can be performed and is not affected by 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, wherein the laminated structure comprising the resin ribs and the top layer laminated on the surface of the foamed resin base material is employed in whole or in part, the method for forming the laminated structure When the foamed resin sheet, which is the material of the foamed resin base material, is set in the molded upper and lower molds in the mold open state after heat softening treatment, a movable gate arranged in the molded lower mold is placed in the hole of the foamed resin sheet. Insert the foamed resin sheet into the proper position and insert the foamed resin sheet into the required shape by clamping the upper and lower molds to mold the foamed resin sheet into the required shape. A foamed resin base for integrating a resin rib having a predetermined pattern shape on the back surface of the foamed resin base material by injecting and filling molten resin into the groove portion of the molded lower mold from the first injection machine attached to the molded lower mold The material and resin rib molding process and the molding upper mold are retracted in the mold opening direction to secure a cavity for forming the top layer with a predetermined clearance between the surface of the foamed resin substrate and the molding upper mold. The top layer is laminated and integrated on the surface side of the foam resin base material by injecting and filling molten resin from the second injection machine attached to the mold into the top layer forming cavity through the hole of the foam resin base material. Forming the top layer
It is characterized by comprising.

  Here, the molding die used for the manufacturing method of the interior parts for automobiles is molded into a required shape, and is integrated with a foamed resin base material that is lightweight and has shape retention, and a back surface of the foamed resin base material. A molding die for molding a laminated structure including a resin rib having a predetermined pattern shape and a top layer laminated on the surface of a foamed resin base material, the molding die being a mold that can be clamped and opened Melted to the surface side of the foamed resin base material through the hole of the foamed resin base material, the first injection machine that is connected to the top mold and the bottom mold, and is connected to the bottom mold and supplies the molten resin that is the material of the resin rib It is composed of a second injection machine for supplying resin, a movable gate capable of moving up and down, which is a supply port of molten resin supplied from the second injection machine, and a drive mechanism for this movable gate, It is characterized by the fusion of two-stage injection function

  And the manufacturing method of the interior component for motor vehicles concerning this invention is characterized by manufacturing a laminated structure in each following process. That is, the process is generally composed of three steps: a foamed resin sheet setting process, a foamed resin base material and resin rib molding process, and a top layer molding process.

  Foamed resin sheet setting step: When the molded upper and lower molds are in the mold open state, the foamed resin sheets are heat-softened to a predetermined temperature by a separate dedicated heating device and then put into the molded upper and lower molds. At this time, the foamed resin sheet is positioned at an appropriate position by fitting the hole formed in the foamed resin sheet into the convex part of the movable gate which is the gate of the top layer.

  Molding process of the foamed resin base material and the resin rib: When the setting of the foamed resin sheet is completed, the molding upper mold moves downward by a predetermined stroke, and the foamed resin sheet is drawn along the cavity shape by clamping the mold upper and lower molds, A foamed resin base material is formed into a desired curved shape. At this time, it is preferable that the upper end of the movable gate which is the resin passage of the top layer is in contact with the upper mold. Simultaneously with the molding of the foamed resin base material, the molten resin, which is the material of the resin rib, is injected and filled into the groove portion of the molding lower mold from the first injection machine, and the resin rib having a predetermined pattern shape is the back surface of the foamed resin base material. Integrated on the side.

  Molding process of the top layer: After the molding process of the foamed resin base material and the resin rib, the molding upper mold moves backward by a predetermined stroke in the mold opening direction, and between the surface of the foamed resin base material and the mold surface of the molding upper mold A top layer forming cavity equal to the thickness of the top layer is formed over the entire surface, and a soft resin molten resin is injected and filled from the second injection machine through the movable gate into the top layer forming cavity, and a foamed resin base material is formed. The top layer is integrated over the entire surface. At this time, the movable gate is lowered to the lower mold surface.

  Therefore, according to the method of the present invention, it is only necessary to mold the resin rib having a reduced projected area and the top layer having a thin thickness compared to the conventional resin core material having a large projected area. It can be set lower than the conventional one, the load on the molding die is small, the amount of resin is small, the material cost can be saved, and the cooling time can be reduced as compared with the conventional resin core material.

  Furthermore, according to the method of the present invention, after the foamed resin base material and the resin rib are molded, a new method in which a top layer is injection-molded on the surface of the foamed resin base material is employed. Even if this occurs, the top layer does not pick up shrinkage distortion and is not adversely affected by appearance. Furthermore, since the top layer is not formed by drawing the sheet material, the degree of freedom of modeling is greatly improved, such as no restriction on the development rate, and drawing transfer can be performed well.

  Also, after molding the foamed resin base material and resin ribs with a molding die, the top layer is injection-molded in a continuous process, so the top layer is supplied as a sheet material as before, and after the sizing cut processing, the foamed resin Compared to the method of press forming by laminating with a sheet, the total number of steps can be shortened and the degree of modeling freedom can be improved.

  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. Since it is comprised from the material, the resin rib integrated with the back surface of this foamed resin base material, and the top layer which has the cushioning property laminated | stacked and integrated on the surface of the foamed resin base material, the conventional weight increases Since the resin core material can be abolished, it is lightweight, low-cost, and is a porous material, so that it has the effect of providing an automotive interior part with 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, and after the resin ribs are injection molded, the upper mold is moved in the mold opening direction. A new cavity is formed by retreating a predetermined stroke, and a soft resin material is injected and filled into the cavity and the top layer is injection-molded. There is no sink mark on the appearance. 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 the transfer of drawn patterns and the like can be easily performed. Can be improved. In addition, compared with the conventional method of forming the top layer from a sheet material, the total man-hours can be reduced, the manufacturing cost can be reduced, 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. 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. 14 show an embodiment of the present invention. FIG. 1 is a front view showing a two-tone type automobile door trim, FIG. 2 is a sectional view showing the configuration of the automobile door trim, and FIG. FIG. 4 is a sectional view showing the structure of the door trim upper, FIG. 5 and FIG. 6 show a molding die used in the manufacturing method of the door trim for the automobile, and FIG. 5 shows the molding metal. FIG. 6 shows a partial cross-sectional view of the mold. 7 to 14 show the respective steps in the manufacturing method of the door trim for the automobile, FIG. 7 is an explanatory view showing the preheating step of the foamed resin sheet, and FIG. 8 is the step of setting the foamed resin sheet into the molding die. FIG. 9 is an explanatory view showing the relationship between the foamed resin sheet and the movable gate in the foamed resin sheet setting step, FIG. 10 is an explanatory view showing the press molding step of the foamed resin base material, and FIG. 11 is a resin rib. FIG. 12 is an explanatory diagram showing the mold back process, FIG. 13 is an explanatory diagram showing the state of the movable gate in the cabinet back process, and FIG. 14 is an explanatory diagram showing the top layer molding process. .

  First, based on FIG. 1 thru | or FIG. 4, the structure of the two-tone type vehicle door trim 20 to which the structure of the interior part for motor vehicles concerning this invention is applied is demonstrated. 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. The door trim lower 40 is provided with a door pocket opening 23, and a pocket back cover (made of a resin molded body) 24 is attached to the rear side of the door trim lower 40 as shown in FIG. A speaker grill 25 is provided on the front side of the door 40 integrally with the door trim lower 40 or separately.

  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 top layer 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 expansion ratio of the foamed resin base material 31 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 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 FIGS. 1 to 3 includes the door trim upper 30 made of a laminated structure and the door trim lower 40 which is a single synthetic resin, and has an excellent appearance design due to an accent effect on the appearance. It has sex. Further, the door trim upper 30 is composed of a foamed resin base material 31 having a shape retaining property and a resin rib 32 laminated and integrated on the back surface of the foamed resin base material 31. The resin core material that has been occupied can be abolished and the lightweight foamed resin base material 31 is used. On the other hand, the resin rib 32 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.

  Moreover, the top layer 33 is laminated and integrated by injection molding over the entire surface of the foamed resin base material 31, and the thickness is set to 0.3 to 1.0 mm. Further, as the material, a soft resin material is preferable, and a thermoplastic elastomer such as TPO (thermoplastic olefin), a soft vinyl chloride resin, a synthetic rubber material such as EPDM, or the like is suitable.

  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 in shape is integrated, and a top layer 33 having a decoration 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 top layer 33 on the surface of the foamed resin base material 31 by injection molding, compared with conventionally drawing-molding a sheet-like decorating material, an expansion rate etc. There is no limit, and the degree of freedom of modeling can be dramatically improved, and the drawing pattern can be easily transferred without a vacuum suction mechanism. When the resin rib 32 is molded, shrinkage after molding Sinking can be reliably prevented from occurring on the surface of the product due to distortion, and the appearance performance is improved, which is 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 34 is formed at the lower edge of the door trim upper 30 so as to correspond to the boss 41 for the installation. After the mounting boss 41 is inserted into the mounting hole 34, 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 the like. 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, based on FIG. 5, FIG. 6, the structure of the shaping die 50 is demonstrated. The molding die 50 is used for molding the door trim upper 30. The molding die 50 includes a molding upper mold 60 that can move up and down by a predetermined stroke, a molding lower mold 70 that is paired with the molding upper mold 60, and two injection machines 80 that are connected to the molding lower mold 70. , 81 (referred to as a first injection machine 80 and a second injection machine 81).

  More specifically, the molding upper die 60 has a cavity portion 61 that matches the product shape, and is driven up and down by a predetermined stroke by an elevating cylinder 62 connected to the upper surface of the molding upper die 60. In addition, guide bushes 63 are provided at the four corners of the molding upper die 60. On the other hand, the molding lower die 70 is provided with a core portion 71 corresponding to the cavity portion 61 of the molding upper die 60. Further, the molding lower mold 70 is provided with a hot runner 72 and a gate 73 which are resin passages for molding the resin rib 32, and a hot runner 74 which is a passage of a resin material for molding the top layer 33 ( A movable side runner 74a and a movable side runner 74b) and a movable gate 75 are provided.

  Further, a movable side runner 74 b and a cylinder 76 that moves the movable gate 75 up and down are arranged in the lower mold 70. The movable gate 75 is positioned above when the foamed resin base material 31 and the resin rib 32 are molded, and is preferably in contact with the mold surface of the molding upper mold 60. When the top layer 33 is molded, It is lowered to the lower position, that is, the mold surface position of the molding lower mold 70. The movable gate 75 is moved up and down by the cylinder 76 between the upper position and the lower position. Note that the molten resin M1 for the resin rib 32 supplied from the first injection machine 80 is in a groove portion 77 formed along the predetermined pattern shape on the mold surface of the lower mold 70 through the hot runner 72 and the gate 73. The resin rib 32 that is injected and filled to match the shape of the groove 77 is formed.

  On the other hand, the molten resin M2 for the top layer 33 supplied from the second injection machine 81 is connected to the runners 74a and 74b after the runner passages of the fixed runner 74a and the movable runner 74b communicate with each other by driving the cylinder 76. The top layer 33 is injected and filled into the cavity C for forming the top layer through the movable gate 75, and the top layer 33 is integrally formed on the surface side of the foamed resin base material 31. In addition, guide posts 78 serving as a guide mechanism project from the four corners of the molding lower die 70. The guide posts 78 are guide bushes 63 of the molding upper die 60 when the molding upper and lower dies 60, 70 are clamped. By being guided in, the press posture of the forming upper die 60 can be properly maintained. In this embodiment, the shim mechanism to be mounted on the guide post 78 is omitted because it is not a main part. However, in order to maintain the mold clearance with high accuracy by changing the mold clearance of the molded upper and lower molds 60 and 70. It is good to arrange a shim mechanism.

  The molding die 50 is configured as described above, and a molding method for molding the door trim upper 30 shown in FIGS. 3 and 4 using the molding die 50 will be described. First, as shown in FIG. 7, the foamed resin sheet S, which is the material of the foamed resin base material 31, is heated and softened to a predetermined temperature using a heater device 90. 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. In addition, compared with the prior application example, since the single sheet of the foamed resin sheet S is heat-softened and set in a mold, the handling property is excellent and the workability is improved.

  Next, an operation procedure for setting the heat-softened foamed resin sheet S in the molding die 50 will be described with reference to FIGS. As shown in FIG. 8, when the molding upper mold 60 is in the upper position, the foamed resin sheet S heated and softened up to a predetermined temperature in the preheating process is positioned and set in the molds of the molding upper and lower molds 60 and 70. As shown in FIG. 2, the movable gate 75 disposed in the molding lower mold 70 faces the cavity, and a hole a is formed in the foamed resin sheet S, and the movable gate 75 enters the cavity through the hole a. The foamed resin sheet S is set so that it faces. In other words, since the foamed resin sheet S can be positioned easily and accurately by fitting the movable gate 75 into the hole a of the foamed resin sheet S, the positioning operation with high accuracy using the movable gate 75 is possible. Can be expected. At this time, the movable gate 75 protrudes upward by the extension operation of the cylinder 76.

  Next, as shown in FIG. 10, the molding upper mold 60 is lowered by a predetermined stroke by driving the lifting cylinder 62, the molding upper and lower molds 60, 70 are clamped, and the foamed resin sheet S follows along the cavity shape. Thus, the foamed resin base material 31 is formed into a desired curved surface shape. Then, as shown in FIG. 11, Sumitomo Nobrene BUE81E6 (polypropylene manufactured by Sumitomo Chemical Co., Ltd., melt index = 65 g / 10 min) is used as the molten resin M1, for example, the molten resin M1, from the first injection machine 80. By injecting and filling the molten resin M1 into the groove 77 of the lower mold 70 through the hot runner 72 and the gate 73, resin ribs 32 having a predetermined pattern shape are formed on the back surface of the foamed resin base 31 as shown in FIG. Is integrated. The injection filling timing of the molten resin M1 may be performed simultaneously with the mold clamping of the molded upper and lower molds 60 and 70, or after the mold upper and lower molds 60 and 70 are clamped, by setting a time lag. good. Furthermore, the mold clearance at the time of injection filling of the resin rib 32 is set narrower than the mold clearance at the time of press molding of the foamed resin base material 31, and injection filling of the molten resin M1 with improved sealing performance is performed. preferable.

  When the molding of the foamed resin base material 31 and the resin rib 32 is completed, the molding upper mold 60 is moved backward in the mold opening direction as shown in FIG. 12, and the foamed resin base material as shown in FIG. A top layer forming cavity C having a thickness of 0.3 to 1.0 mm for forming the top layer 33 is secured between the surface of 31 and the mold surface of the molding upper mold 60. At this time, by driving the cylinder 76, the movable side runner 74 b that is a passage for the resin material for the top layer 33 and the movable gate 75 are both lowered by the contraction operation of the cylinder 76, and the upper end of the movable gate 75 is the bottom of the molding lower mold 70. It is flush with the mold surface.

  Therefore, as shown in FIG. 14, the soft molten resin M2 is injected and filled from the second injection machine 81 into the cavity C for forming the top layer through the hot runner 74 and the movable gate 75 through the hole 31a of the foamed resin base material 31. Then, the top layer 33 is injection-molded over the entire surface of the foamed resin base material 31 in a process continuous with the molding process of the foamed resin base material 31 and the resin rib 32.

  The top layer 33 is formed by injection-filling a soft molten resin M2 in a space between the surface of the foamed resin base material 31 and the mold surface of the molding upper mold 60. Compared to the conventional method of drawing, sharp shapes such as highlight lines can be created, there is no restriction on the expansion rate, the degree of freedom of modeling can be dramatically improved, and no vacuum forming mechanism is attached. The drawn pattern can be easily transferred from the upper mold 60 during injection molding. Moreover, there is no conventional problem that the shrinkage distortion of the resin rib 32 appears as a sink on the product surface, and the appearance performance can be greatly improved. Furthermore, as in the past, the decorative sheet material is formed by extruding, calendering, etc., and then the sheet is cut, and then the foamed resin sheet is laminated to form a molding material. There is an advantage that the labor can be saved and the molding cost can be greatly reduced.

  In the present embodiment, the door trim upper 30 formed using the molding die 50 and the door trim lower 40 molded separately using an injection molding die are integrally joined by ultrasonic processing to manufacture the door trim 20. The mold may be equipped with three injection machines, and the door trim upper 30 and the door trim lower 40 may be integrated with the same molding die.

  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, trunk trims, luggage trims, roof trims, and rear side trims.

It is a front view which shows the Example which applied the interior component for motor vehicles which concerns on this invention to the door trim for two-tone type vehicles. 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 a general view which shows one Example of the shaping die used for shaping | molding of the door trim upper shown in FIG. It is explanatory drawing which shows the relationship between the movable gate and cylinder in the molding die shown in FIG. It is explanatory drawing which shows the pre-heating process of the foamed resin sheet in the manufacturing method of the door trim upper shown in FIG. It is explanatory drawing which shows the setting process in the molding die of the foamed resin sheet in the manufacturing method of the door trim upper shown in FIG. It is explanatory drawing which shows the locating relationship of the movable gate and foamed resin sheet in the setting process of the foamed resin sheet 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 upper shown in FIG. It is explanatory drawing which shows the injection molding process of the resin rib in the manufacturing method of the door trim upper shown in FIG. It is explanatory drawing which shows the mold back mold back process in the manufacturing method of the door trim upper shown in FIG. FIG. 13 is an explanatory diagram showing a relationship between a movable side gate and a top layer forming cavity in the cavity back step shown in FIG. 12. It is explanatory drawing which shows the injection molding process of the top layer in the manufacturing method of the door trim upper shown in FIG. It is a front view which shows the conventional door trim for motor vehicles. It is XVI-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 XIX-XIX 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 31 Foamed resin base material 31a Hole 32 Resin rib 33 Top layer 40 Door trim lower (single resin product)
DESCRIPTION OF SYMBOLS 50 Molding die 60 Molding upper mold 61 Cavity part 62 Cylinder 63 Guide bush 70 Molding lower mold 71 Core part 72 Hot runner 73 Gate 74 Hot runner 74a Fixed side runner 74b Movable side runner 75 Movable gate 76 Cylinder 77 Groove part 78 Guide post 80 First injection machine 81 Second injection machine 90 Heater device S Foamed resin sheet M1 Molten resin (for resin rib formation)
M2 molten resin (for top layer formation)
C Top layer forming cavity a Hole

Claims (3)

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 top layer (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), the heat-softened foamed resin sheet (S) is set in the molded upper and lower molds (60, 70), and the molded upper and lower molds (60, 70). ) Is clamped into a desired curved surface shape, and a resin rib (32) having a predetermined pattern shape that reinforces rigidity on the back surface side of the foamed resin base material (31) is provided with the foamed resin base. An interior part for an automobile, wherein a top layer (33) for improving cushioning and design properties is laminated and integrated on the surface side of the material (31). 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 top layer (33) laminated on the surface of the resin base material (31) in whole or in part,
The laminated structure (30) is molded by placing the foamed resin sheet (S), which is the material of the foamed resin base material (31), in the molded upper and lower molds (60, 70) in an open state after heat softening. When setting, the foamed resin sheet (S) is inserted into the hole (a) of the foamed resin sheet (S) by inserting the movable gate (75) disposed in the molded lower mold (70) to set the foamed resin sheet (S) at an appropriate position. (S) the setting process;
The molded upper and lower molds (60, 70) are clamped to draw the foamed resin sheet (S) into the required shape to form the foamed resin base material (31) into the required shape, and the molded lower mold (70). The molten resin (M1) is injected and filled into the groove portion (77) of the molded lower mold (70) from the attached first injection machine (80), whereby the resin rib (32) having a predetermined pattern shape is formed into a foamed resin base. Molding step of the foamed resin base material (31) and the resin rib (32) integrated with the back surface of the material (31);
The molding upper mold (60) is moved backward in the mold opening direction to secure a top layer forming cavity (C) with a predetermined clearance between the surface of the foamed resin base material (31) and the molding upper mold (60). In the top layer forming cavity (C), the molten resin (M2) is passed through the hole (31a) of the foamed resin base material (31) from the second injection machine (81) attached to the molding lower die (70). A step of forming the top layer (33) by laminating and integrating the top layer (33) on the surface side of the foamed resin base material (31)
A method for producing an interior part for an automobile, comprising: 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 A molding die (50) for molding a laminated structure (30) comprising a top layer (33) laminated on the surface of a resin substrate (31),
The molding die (50) is connected to the molding upper mold (60) and the molding lower mold (70) that can be clamped and opened, and is a material for the resin rib (32). The molten resin (M2) is supplied to the surface side of the foamed resin base material (31) through the first injection machine (80) for supplying the molten resin (M1) and the hole (31a) of the foamed resin base material (31). A second injection machine (81) to be moved, a movable gate (75) capable of moving up and down, which is a supply port for the molten resin (M2) supplied from the second injection machine (81), and the movable gate (75) A molding die for a laminated structure, which is composed of a driving mechanism (76), and has a cold press function and a two-stage injection function fused together.

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