JP2006123207A - Trim part for car and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve the weight reduction of a trim part including a laminated structure in a part thereof and to enhance the moldability of a foamed resin base material. <P>SOLUTION: A door trim 10 is constituted of a laminated structure (door upper) 20, which is constituted by integrally laminating a resin rib 22 to the back of the lightweight foamed resin base material 21 having shape retention and laminating a decorative material 23 on the surface of the foamed resin base material 21, and a resin single product (door trim lower) 30 and, since a drawdown suppressing layer 24 for suppressing drawdown is integrated with one side of a foamed resin sheet S subjected to heating softening treatment at a high temperature, the foamed resin sheet S is easy to handle even if heat-treated at a high temperature and, since the foamed resin sheet S does not sag when it is set to a mold 40, the moldability of the foamed resin base material 21 is enhanced, the decorative material 23 in which a heating process is abolished is superposed on the foamed resin sheet S and softened by the remaining heat of the foamed resin sheet S to be integrally molded. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to interior parts for automobiles such as door trims, rear parcel shelves, floor trims, trunk trims, rear side trims, pillar garnishes, roof trims, etc., and manufacturing methods thereof. The present invention relates to an excellent automotive interior part and a method for manufacturing the same.

  For example, the configuration of automobile interior parts will be described with reference to FIGS. The door trim 1 has shape retention and attachment rigidity to a vehicle body panel, and is configured by laminating and integrating a skin 3 excellent in surface appearance on the surface of a resin core material 2 extending over almost the entire product surface. . Reference numeral 2a denotes an inner seal mounting flange for mounting the inner seal. The resin core material 2 is made of polypropylene resin mixed with talc, and the skin 3 itself does not have shape retention, such as a vinyl chloride sheet, a thermoplastic olefin (hereinafter referred to as TPO) sheet, or the like. The synthetic resin sheet is usually used.

  Next, a conventional example of the method for forming the door trim 1 will be described with reference to FIG. First, a molding die 4 that molds the door trim 1 is connected to a molding upper die 5 that can move up and down by a predetermined stroke, a molding lower die 6 that forms a pair with the molding upper die 5, and a molding lower die 6. It is generally composed of the injection machine 7. When the upper and lower molds 5 and 6 are clamped, a cavity portion 5a is formed in the molded upper mold 5 and a core section 6a is provided in the molded lower mold 6 in order to shape the product shape of the door trim 1. Yes. In order to move the molding upper die 5 up and down by a predetermined stroke, an elevating cylinder 5b is connected, and the molding lower die 6 is provided with a manifold 6b and a gate 6c that serve as a passage of molten resin from the injection machine 7. Further, in order to maintain an appropriate posture, the upper molding die 5 that moves up and down is provided with guide posts 6d at the four corners of the lower molding die 6, and the molding upper die 5 has guides corresponding to the guide posts 6d. A bush 5c is provided.

  Therefore, when the molding upper and lower molds 5 and 6 are in the mold open state, the skin 3 is set in the mold, and then the molding upper and lower molds 5 and 6 are clamped and then injected into the product cavity between both molds. By injecting and filling the molten resin M from the machine 7 through the manifold 6b and the gate 6c, the resin core material 2 is formed into a required curved shape, and the skin 3 is integrally formed on the surface of the resin core material 2 (for example, , See Patent Document 1). In FIG. 14, for convenience of explanation, the molten resin M is supplied to the mold surface of the core portion 6 a in an open state, but the molten resin M is injected and filled into the cavity after the mold upper and lower molds 5 and 6 are clamped. May be.

Japanese Patent Laid-Open No. 10-138268 (Page 2, FIGS. 3 and 4)

  However, in the conventional door trim 1, since the projected area of the resin core material 2 is large, there are problems that the material cost is high and the product is heavy. In addition, since the projected area of the resin core material 2 is large, it is necessary to set the injection pressure at the time of molding high, and a mold structure that can withstand the high injection pressure is required. In addition, since a large amount of molten resin is cooled and solidified, the molding cycle becomes longer, which is a major factor for reducing productivity.

  The present invention has been made in view of such circumstances, and can produce automobile interior parts that can promote weight reduction and contribute to cost reduction.In particular, while enhancing the appearance and feel of the product surface, It is an object of the present invention to provide an automotive interior part and a method for manufacturing the same that are free from shrinkage deformation after molding and that can improve molding accuracy.

  As a result of earnest research, the present inventors have given the function as a core material by imparting shape retention to the foamed resin sheet that has been used conventionally as the skin, and more. In places where rigidity is required, that is, peripheral parts and panels of products, parts mounting places and parts where loads are applied, resin ribs with excellent rigidity are arranged, and other parts are made into a hollow shape, In addition to providing interior trim parts that are lighter and less expensive than conventional resin cores with a large projected area, the molding temperature is particularly high considering the properties of the foamed resin sheet and the decorative sheet that is affixed to the surface. If the foamed resin sheet is treated at a high temperature, the shrinkage deformation after molding will be small, and if the decorative sheet is treated at a low temperature, the appearance performance and feel of the product surface will be improved. It was finding the Rukoto. However, when the foamed resin sheet is treated at a high temperature, the drawdown phenomenon is large, and as a result, the molded product of the foamed resin sheet has a thickness variation, and the higher the temperature, the more the degree of drawdown, that is, the deviation of the product thickness. In view of the tendency to increase, it was considered that suppressing the drawdown phenomenon of the foamed resin sheet is an important factor in increasing the molding accuracy, and the present invention has been completed.

  That is, an automotive interior part according to the present invention is a resin resin having a predetermined pattern shape that is molded into a required shape, is lightweight and has shape retention, and is laminated and integrated on the back surface of the foam resin substrate. In an interior part for an automobile in which a laminated structure composed of a rib and a decorating material attached to the surface of the foamed resin base material is employed in whole or in part, the laminated structure is the foamed resin base material In a state where the drawdown suppression layer is laminated on at least one surface of the foamed resin sheet which is a material of the above, the sheet thickness of the foamed resin sheet heat-softened to high temperature is maintained substantially constant by the drawdown suppression layer, The foamed resin sheet is placed in a molding die, and a heat treatment is omitted on its upper surface or a decorating material subjected to a low temperature heat treatment is placed on the foamed resin sheet. Wherein the decorative material to the surface of the foamed resin base material at a low pressure of the press by clamping of the mold are integrated.

  Here, as an interior part for an automobile, as long as it has a structure including at least a part of a laminated structure, for example, a door trim, a rear parcel shelf, a floor trim, a luggage trim, a trunk trim, a rear side trim, Applicable to pillar garnish, roof trim, etc.

  Furthermore, the laminated structure is molded into a desired curved shape, is lightweight and has a shape-retaining foamed resin base material, and a resin rib having a predetermined pattern shape laminated and integrated on the back surface of the foamed resin base material. The foamed resin base material is formed into a required curved shape in the molding die after heat-softening the foamed resin sheet. The shape is retained by molding. The term “shape retention” as used herein refers to having sufficient rigidity to retain the shape at least when the mold is removed after molding, even without a reinforcing material such as a rib.

  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, polyacetal resin, polyethylene terephthalate resin, polyvinyl alcohol resin, polyamide resin, vinyl chloride resin, ionomer resin, acrylonitrile / butadiene / styrene (ABS) Resin, polycarbonate resin and the like can be used. As the foaming agent, an azo compound such as azodicarbonamide, an organic foaming agent such as 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, polyacetal resins, polyethylene terephthalate resins, polyvinyl alcohol resins, polyamide resins, vinyl chloride resins, ionomer resins, acrylonitrile / butadiene / Styrene (ABS) resin, polycarbonate resin and the like can be used. Moreover, you may mix various fillers in these thermoplastic resins. Examples of the filler that can be used include inorganic fibers such as glass fiber and carbon fiber, and inorganic particles such as talc, clay, silica, and calcium carbonate. Moreover, various additives, such as antioxidant, a ultraviolet absorber, a coloring agent, a flame retardant, and a low shrinkage agent, may be mix | blended.

  And in order to improve an external appearance design property, the decorating material is integrated with the surface of the foamed resin base material. As the decorating material, a thermoplastic resin sheet such as TPO or thermoplastic urethane (hereinafter referred to as TPU), or a fabric sheet such as a woven fabric, a nonwoven fabric, or a knitted fabric can be used. Further, a foamed resin sheet such as polyurethane foam, polyethylene foam, polypropylene foam or the like can be laminated and integrated as a cushion layer on the back surface of a fabric sheet such as thermoplastic resin sheet, woven fabric, nonwoven fabric, knitted fabric or the like. Moreover, you may integrate a nonwoven fabric layer with the back surface of a cushion layer. In addition, using TPO sheet and PE foam as the material for the decorating material, and using olefin resin as the material for the foamed resin base material and resin rib, all materials can be unified into olefin resin, which is preferable for recycling. .

  Furthermore, the foamed resin sheet needs to be heated to a high temperature in consideration of moldability. In order to avoid a drawdown phenomenon during high temperature heating, a drawdown suppression layer is provided on at least one surface of the foamed resin sheet. Laminated. As this drawdown suppression layer, a nonwoven fabric (nonwoven fabric based on high melting point fibers) is preferable. In addition, a hot melt film is usually used as an adhesive means for adhering the foam resin base material and the decorating material. Even if this hot melt film is laminated on the foam resin sheet side, the decorating material side May be laminated.

  Here, the molding die used for the integrated construction method of the foamed resin sheet and the decorating material is composed of a pair of split molds and an injection machine attached to the mold on one side. For example, it is comprised from the shaping | molding upper die which can be moved up and down, the shaping | molding lower die which is a fixed side located in the downward side of a shaping | molding upper die, and the injection machine connected with a shaping | molding lower die. When the molding upper and lower molds are used, the molten resin supplied from the injection machine passes through resin passages such as a manifold and a gate provided in the molding lower mold, that is, on the mold surface of the molding lower mold, that is, the mold of the molding lower mold. Molten resin is supplied to a groove portion (corresponding to a resin rib shape) formed in the surface.

The foamed resin base material and the decorative material are integrally press-molded with the molding die, but the foamed resin sheet that is the material of the foamed resin base material is heated to 160 to 220 ° C. by the heater device, and the decorative material is The heating step is abolished, or the heating process is kept at a low temperature of 120 ° C. or lower even when heated. When the mold is opened, the heat-softened foamed resin sheet is overlaid with a decorative material that has been heat-treated or heated at a low temperature, and the mold is clamped to the product shape. It becomes. Also, pressing pressure of the mold at this time is 0~40kgf / cm ^2, compared to the pressing pressure 80 ± 20kgf / cm ² at the time of a conventional press molding, can be set low press pressure.

  And according to the interior parts for automobiles concerning the present invention, as a structure of a laminated structure, a lightweight foamed resin base material, a hollow resin rib disposed on the back side thereof, and a foamed resin base material surface Since it is comprised from the decorating material affixed on, weight reduction can be achieved by abolishing the conventional heavy resin core material.

  Furthermore, since a temperature difference is set between the molding temperature of the foamed resin sheet and the decorating material, thermal deformation does not occur on the surface of the decorating material, and good appearance performance and feeling of touch can be obtained. Moreover, since it becomes possible to heat the foamed resin sheet to a high temperature by providing the drawdown suppressing layer on the foamed resin sheet, there is no shrinkage deformation after molding, and the action of the drawdown suppressing layer The product thickness can be maintained almost constant, and the molding accuracy of the foamed resin substrate can be increased.

  Next, another embodiment of the present invention is a foamed resin base material that is molded into a required shape, is lightweight and has shape retention, and a predetermined pattern shape that is laminated and integrated on the back surface of the foamed resin base material. In a method for manufacturing interior parts for automobiles, in which a laminated structure composed of a resin rib and a decorative material affixed to the surface of the foamed resin base material is used in whole or in part, the foamed resin sheet is heated and softened. The foamed resin sheet that has been treated and heat-softened and the heat treatment is omitted, or a low-temperature heat-treated decorative material is placed in the molding die, and a drawdown phenomenon is likely to occur in the foamed resin sheet. Hot air or hot air supplied from the blow mechanism is forcibly blown from the concave surface of the molded lower mold toward the back side of the foamed resin sheet to suppress the drawdown of the foamed resin sheet. Tighten, After press molding with pressure, the resin rib is injected into the groove part of the molding lower mold at the timing just before or after mold clamping of the molding die, so that the resin rib becomes the back surface of the foamed resin base material. A method for forming a laminated structure in which a laminated structure is formed by laminating and integrating on the side is employed.

  Therefore, according to this embodiment, the foamed resin sheet and the decorating material are separately put into the molding die, but the foamed resin sheet can be molded even if heated to a considerably high temperature in order to improve moldability. When the foamed resin sheet is placed in the mold, the blown resin sheet is heated or blown from the blow mechanism, so the foamed resin sheet does not cause the drawdown phenomenon. During molding, a substantially uniform wall thickness can be secured.

  Furthermore, if a drawdown suppressing layer such as a nonwoven fabric is formed on at least one surface of the foamed resin sheet used in this method, the drawdown phenomenon of the foamed resin sheet can be more effectively prevented and the moldability can be further improved. it can.

  As described above, according to the automotive interior component of the present invention, the foamed resin base material that is lightweight and has shape retention, the resin rib laminated and integrated on the back surface of the foamed resin base material, and foaming The entire structure or at least a part of the laminated structure composed of the decorative material affixed to the surface of the resin base material makes it possible to eliminate the conventional heavy resin core material. It has the effect that it can provide interior parts for automobiles at low cost.

  Further, according to the method for manufacturing an automotive interior part according to the present invention, the foamed resin sheet as the material of the foamed resin base material is heat-softened, but the decorating material abolishes the heating process or heats it. However, while adopting a construction method in which both materials are put into the mold while kept at low temperature heating, the foamed resin sheet to be treated at high temperature is laminated with a drawdown suppression layer, or the mold Since the blow mechanism that suppresses the drawdown is provided, it is possible to reliably avoid the drawdown of the foamed resin sheet. Accordingly, it is possible to improve the appearance performance and the touch feeling of the product, to suppress the shrinkage deformation after the molding, and to eliminate the thickness variation.

  Hereinafter, a preferred embodiment of an automobile interior part according to the present invention will be described by illustrating an automobile door trim.

  1 to 8 show an embodiment of the present invention, FIG. 1 is a front view showing a two-tone type automobile door trim, FIG. 2 is a sectional view showing the structure of the automobile door trim, and FIG. 4 is a front view showing a resin rib and a door trim lower of the door trim upper in FIG. 4, FIG. 4 is an explanatory view showing an outline of a manufacturing method of the door trim for the automobile, and FIG. 5 is a foamed resin sheet and a drawdown used for the door trim upper It is explanatory drawing which shows the lamination process with a suppression layer. 6 to 8 are explanatory views showing each step of the method for manufacturing the automobile door trim.

  1 and 2, a two-tone type automobile door trim 10 is composed of an upper and lower divided body of a door trim upper 20 made of a laminated structure and a door trim lower 30 made of a single resin product. As functional components to be mounted on the door trim 10, an inside handle escutcheon 11 and a power window switch escutcheon 12 are attached to the door trim upper 20. On the other hand, the door trim lower 30 is provided with a door pocket opening 13, and a pocket back cover (made of a resin molded body) 14 is attached to the rear side of the door trim lower 30, as shown in FIG. The speaker grill 15 is formed integrally with or separately from the door trim lower 30 on the front side.

  By the way, the door trim 10 for automobiles according to the present invention is characterized in that the door trim upper 20 which is a laminated structure is reduced in weight, and the appearance performance and touch feeling of the door trim upper 20 are improved. That is, as shown in FIG. 2, the door trim upper 20 is molded into a desired curved surface shape and has a foamed resin base material 21 having shape retention, and a reinforcement integrated and laminated on the back surface side of the foamed resin base material 21. The resin rib 22 having a function and a decorating material 23 having a decorating function laminated and integrated on the surface side of the foamed resin base material 21 are roughly constituted. Furthermore, in this embodiment, the drawdown suppression layer 24 is laminated on the side surface of the foamed resin base material 21 facing the decorating material 23. In the figure, reference numeral 25 denotes a hot melt film, and reference numeral 16 in the figure denotes a vehicle body panel. In addition, the foamed resin base material 21 is heat-softened to heat the foamed resin sheet so as to have shape retention, and then thermoformed into a required shape, for example, cold press-molded with a molding die having a desired mold surface. In addition, the foamed resin base material 21 may be shaped by vacuum forming for a portion with a higher development rate.

  The foamed resin sheet has a configuration 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 polyacetal resin, a polyethylene terephthalate resin, a polyvinyl alcohol. Resin, polyamide resin, vinyl chloride resin, ionomer resin, acrylonitrile / butadiene / styrene (ABS) resin, polycarbonate resin, etc. can be used. As foaming agents, azo compounds such as azodicarbonamide, sulfohydrazide compounds Organic foaming agents such as nitroso compounds and azide compounds and inorganic foaming agents such as sodium bicarbonate 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 substrate 21 is set to 2 to 10 times, and the thickness is set to 0.5 to 30 mm, particularly 1 to 10 mm.

  Next, the resin ribs 22 are disposed on the back surface side of the foamed resin base material 21 and, in particular, as shown in FIG. 3, are set in a predetermined pattern extending in an intersecting manner, and a portion to which a load is applied (for example, a clip seat). The portion excluding the upper surface of the waist portion, the upper surface of the armrest portion, etc.) has a thinned shape. In addition, as for this pattern, arbitrary patterns may be selected as long as it is intersecting, such as a vertical and horizontal direction, an oblique direction, or a combination thereof. The resin rib 22 is made of a general-purpose synthetic resin molded body, and a polyethylene resin, a polypropylene resin, a polystyrene resin, a polyacetal resin, a polyethylene terephthalate resin, a polyvinyl alcohol resin, a polyamide as a synthetic resin that can be preferably used normally. Resin, vinyl chloride resin, ionomer resin, acrylonitrile / butadiene / styrene (ABS) resin, polycarbonate resin, etc., and in this embodiment, polypropylene resin in consideration of environmental and recycling aspects. Is used. The resin rib 22 is appropriately mixed with a filler such as inorganic fibers such as glass fiber and carbon fiber, and inorganic particles such as talc, clay, silica and calcium carbonate in the thermoplastic resin. May be.

  As described above, the door trim 10 shown in FIGS. 1 to 3 includes the door trim upper 20 formed of a laminated structure and the door trim lower 30 of a single resin, and has an excellent appearance design due to an accent effect on the appearance. I have. Further, the door trim upper 20 includes a foamed resin base material 21 having shape retention, a resin rib 22 laminated and integrated on the back surface of the foamed resin base material 21, and a decorating material 23 having a decorating property. Therefore, the resin core material occupied over the entire circumference of the product can be abolished as before, and the weight of the product is reduced compared to the conventional example because the lightweight foamed resin base material 21 is used. In addition, the resin material can be saved and the cost can be reduced. Furthermore, since the foamed resin base material 21 has a porous structure, the door trim upper 20 is excellent in sound absorption performance and can reduce noise in the vehicle interior.

  Moreover, the decorating material 23 affixed on the surface of the foamed resin base material 21 is comprised in the present Example from the two-layer laminated structure of the top layer 23a and the cushion layer 23b laminated | stacked and integrated on the back surface. Specifically, a TPU resin sheet is used as the top layer 23a and a polyurethane foam is used as the cushion layer 23b, but a TPO sheet, woven fabric, non-woven fabric, knitted fabric, or the like may be used as the top layer 23a. In addition, as the cushion layer 23b, a foam sheet such as polyethylene foam or polypropylene foam can be used. Moreover, the three-layer laminated structure which backed the back surface nonwoven fabric layer, such as a polypropylene fiber nonwoven fabric, a polyester fiber nonwoven fabric, and a polyester polypropylene polypropylene nonwoven fabric, can also be used for the back surface of the cushion layer 23b.

  Further, an olefin resin is used as the material of the foamed resin base material 21 and the resin rib 22, and in addition to this, the top layer 23a of the decorating material 23 is a TPO sheet, and the cushion layer 23b is an olefin type such as polyethylene foam. When all the resin is unified, it is advantageous in terms of recycling.

  By the way, the door trim 10 is composed of an upper and lower divided body of a door trim upper 20 and a door trim lower 30, and in particular, a temperature difference in molding temperature between the decorating material 23 in the door trim upper 20 and the foamed resin base material 21. By maintaining the surface appearance and feel of the decorative material 23 in a favorable manner, the drawdown suppression layer 24 is laminated on the foamed resin sheet S that is the material of the foamed resin base material 21. Even if the foamed resin sheet S is heated and softened to a higher temperature, the drawdown phenomenon does not occur, the thickness of the product can be maintained uniformly, the molding performance can be improved, the above-mentioned good hand feeling, beautiful There is an advantage that the product value can be improved together with the appearance of the product surface.

  Next, the configuration of the molding die 40 used in the method for manufacturing the door trim 10 will be described based on FIG. 4 for reference. A molding die 40 used for molding the door trim 10 is connected to a molding upper mold 41 that can move up and down by a predetermined stroke, a molding lower mold 42 that is paired with the molding upper mold 41, and a molding lower mold 42. It is mainly composed of two injection machines 43a and 43b. More specifically, the molding upper die 41 has a cavity portion 411 that matches the product shape, and is driven up and down by a predetermined stroke by an elevating cylinder 412 connected to the upper surface of the molding upper die 41. In addition, guide bushes 413 serving as a guide mechanism are provided at the four corners of the molding upper die 41.

  On the other hand, the molding lower die 42 is provided with a core portion 421 corresponding to the cavity portion 411 of the molding upper die 41. Further, in order to supply molten resin to the mold surface of the core portion 421, manifolds 422a and 422b and gates 423a and 423b are provided in the molding lower mold 42. Resins of the manifolds 422a and 422b and gates 423a and 423b are provided. The molten resins M1 and M2 supplied from the injection machines 43a and 43b through the passages are supplied into the groove 424 formed on the upper surface of the core 421 and into the cavity 425 for forming the door trim lower 30. In addition, guide posts 426 that serve as a guide mechanism protrude from the four corners of the molded lower mold 42, and the guide posts 426 guide into the guide bush 413 when the molded upper and lower molds 41 and 42 are clamped. As a result, the pressing posture of the molding upper die 41 can be properly maintained.

When the molding upper mold 41 and the molding lower mold 42 are in the mold open state, the foamed resin sheet S that is the material of the foamed resin base material 21 is introduced. A suppression layer 24 is laminated, and a hot melt film 25 is integrated on the outer surface thereof. In the present embodiment, a nonwoven fabric (a surface density of 20 to 200 g / m ² ) is used as the drawdown suppression layer 24, and a polyethylene film is used as the hot melt film 25. The foamed resin sheet S is heated and softened to a high temperature of 160 to 220 ° C. by the heater device 50, and when the foamed resin sheet S is put into the molding die 40, one side of the foamed resin sheet S (hot melt The decorative material 23 is superimposed on the film 25 (laminate surface). The decorative material 23 is not subjected to heat treatment or is subjected to heat treatment at a low temperature of 120 ° C. or lower even when heat treatment is performed.

  As described above, the decorating material 23 has no heat treatment or low-temperature heat treatment, while the drawdown suppressing layer 24 and the hot melt film 25 are laminated on one surface of the foamed resin sheet S. Since the heat treatment is performed at a high temperature by the heater device 50, when these materials are put into the molding die 40, the foamed resin sheet S in a high temperature state is in a softened state, and a so-called drawdown phenomenon occurs in which the center hangs down due to gravity. Although it is easy, since the drawdown suppression layer 24 is integrated on one surface, the drawdown phenomenon can be effectively suppressed and the conveyance to the molding die 40 can be easily performed. Further, even when placed on the mold surface of the molding lower mold 42, the uneven shape of the molding lower mold 42 does not sag, and as a result, a uniform thickness of the foamed resin substrate 21 can be ensured. . Furthermore, since the decorative material 23 is not subjected to heat treatment or is subjected to low-temperature heat treatment, the product surface of the decorative material 23 is not excessively softened. If it can be avoided and if it is superposed on the heat-treated foamed resin sheet S, the decorating material 23 will be moderately soft due to the residual heat from the foamed resin sheet S, and will follow well along the cavity shape. There is an advantage that the moldability is excellent without causing defects such as cutting.

  The process of laminating the drawdown suppression layer 24 on the foamed resin sheet S will be described with reference to FIG. In the drawing, the foamed resin sheet S is extruded from the extruder 60 and fed in the direction of the arrow. At the time of feeding, the drawdown suppression layer 24 and the hot melt film 25 are fed from the raw fabric rolls 61 and 62, respectively. Is firmly joined and integrated by the residual heat of the foamed resin sheet S and the roll pressure between the pair of pressure-bonding rolls 63, 63.

  Next, each step in which the method of the present invention is applied to the method of manufacturing the two-tone type door trim 10 will be described with reference to FIGS. First, as shown in FIG. 6, the foamed resin sheet S is heated and softened by the heater device 50 such as an infrared heater, and the foamed resin sheet S is put into the molding die 40 in the mold open state. As described above, the draw-down suppressing layer 24 and the hot melt film 25 are laminated on one surface of the foamed resin sheet S. Furthermore, the decorating material 23 is mounted on the upper surface. As the foamed resin sheet S, a polypropylene foam sheet (manufactured by Sumika Plustech, trade name: Sumiceller foam PP sheet, expansion ratio = 3 times, thickness 3 mm) is used. The foam resin sheet S and the decorating material 23 are set at the upper half of the cavity defined by the cavity portion 411 of the molding upper die 41 and the core portion 421 of the molding lower die 42 at the location corresponding to the door trim upper 20. Set to. At this time, since the foamed resin sheet S in the high temperature state does not droop excessively due to the drawdown suppressing layer 24, the conveyance work can be performed smoothly and the drooping is effectively regulated even when set in the molding die 40. it can.

Then, after setting the foamed resin sheet S and the decorating material 23, the raising / lowering cylinder 412 of the molding upper die 41 is operated to lower the molding upper die 41 by a predetermined stroke, and as shown in FIG. 41 and 42 are clamped, the foamed resin sheet S is shaped along a desired mold surface shape, the foamed resin base material 21 is molded into a required shape, and is set on the upper surface of the foamed resin base material 21. The decorative material 23 is integrated. At this time, a pressing pressure of molding upper and lower dies 41, 42 is carried out molding at low pressure press 0~40kgf / cm ^2, half the press pressure than the pressing pressure 80 ± 20kgf / cm ² conventional press molding In addition to reducing the load applied to the molding, the decorating material 23 follows the mold surface shape of the molding upper mold 41 well by the residual heat of the foamed resin sheet S, and the moldability is improved. To do.

  Furthermore, since the decoration material 23 is processed at a low temperature while being low-pressure during press molding, in addition to the above-described good molding performance of the decoration material 23, the flow of the product surface of the decoration material 23, etc. Can be prevented as much as possible. In addition, even when a fabric sheet such as woven fabric, non-woven fabric, or knitted fabric is used as the top layer 23a, it is possible to effectively solve the problem of hair fall caused by excessive heating and high-pressure press, and feel and appearance Thus, the door trim upper 20 can be molded well.

  Then, the foamed resin base material 21 and the decorating material 23 are integrally press-molded by clamping the molding upper and lower molds 41 and 42, and then the resin ribs 22 in the door trim upper 20 from the first injection machine 43a through the manifold 422a and the gate 423a. In order to form the molten resin M1, the groove portion 424 is injected and filled. At this time, compared to the conventional resin core material having a large projected area, the resin injection is sufficient to form the hollow resin ribs 22, so that the injection pressure of the resin can be lowered and the injection pressure can be overcome. It is not necessary to apply a high press pressure to the upper mold, and it is sufficient that a press pressure is applied to the extent that the foamed resin base material 21 and the decorating material 23 can be molded. It is possible to effectively solve the problem that occurs. The injection timing of the molten resin M1 can be set before the mold upper and lower molds 41 and 42 are clamped. Further, as the molten resin M1, a resin in which talc is mixed at an appropriate ratio using Sumitomo Noblen BUE81E6 (polypropylene manufactured by Sumitomo Chemical Co., Ltd., melt index = 65 g / 10 min) is used. Then, as described above, after the integral press molding of the foamed resin base material 21 and the decorating material 23, the molding of the door trim upper 20 is completed by integrally molding the resin rib 22 on the back surface side of the foamed resin base material 21.

  Next, as shown in FIG. 8, in order to mold the door trim lower 30, the molten resin M2 is injected and filled from the second injection machine 43b into the cavity 425 for molding the door trim lower 30 through the manifold 422b and the gate 423b. Lower 30 is formed into a required shape. In this embodiment, the molten resin M2 used as the material of the door trim lower 30 is Sumitomo Nobrene BUE81E6 (polypropylene manufactured by Sumitomo Chemical Co., Ltd., melt index = 65 g / 10 min). In comparison, since the door trim lower 30 appears on the surface of the product, the appearance performance may be improved by mixing the pigment or the like to give a desired color, or by engraving the surface on the surface.

  Further, the molten resins M1 and M2 branched and supplied to the door trim upper 20 and the door trim lower 30 can be supplied from one injection machine 43 as the same material. In this case, a branch manifold serving as a passage for the molten resin M1 supplied to the door trim upper 20 side from the main manifold communicating with the injection machine 43 and a branch manifold for the resin passage supplying the molten resin M2 to the door trim lower 30 side are provided. The molten resins M1 and M2 may be supplied separately, with a time difference. In the above-described process, the molding of the foamed resin base material 21 and the integration of the resin ribs 22 were simultaneously performed using the same molding die 40. However, the foamed resin base material 21 and the resin ribs 22 were separated. It is also possible to mold each of the molds separately and integrate them using a crimping mold. However, in consideration of cost, work efficiency, etc., it is preferable to adopt a process of simultaneously molding the foamed resin base material 21 and the resin rib 22.

  Moreover, since the excessive residual heat is not transmitted from the foamed resin sheet S by laminating the drawdown suppression layer 24 on the surface side facing the decorating material 23 of the foamed resin sheet S, the decorating material 23 is adversely affected by heat. However, it is possible to provide the drawdown suppression layer 24 on the opposite surface of the foamed resin sheet S. Furthermore, although the hot melt film 25 is integrated on the foamed resin sheet S side, the hot melt film 25 can be laminated on the decorating material 23 side. Further, if the decorative material 23 has a function of suppressing the drawdown, the foamed resin sheet S and the decorative material 23 are laminated, and then subjected to heat softening treatment and put into the upper and lower molds 41 and 42. Therefore, the molding process can be simplified.

  9 to 11 show a second embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. Also in this second example, the molding temperature of the foamed resin sheet S and the decorating material 23 is made different, and in particular, the decorating material 23 is treated at a low temperature to ensure good thermal deformation and surface texture, The foamed resin sheet S effectively prevents shrinkage distortion after molding by high-temperature treatment. And in this 2nd Example, when the foamed resin sheet S is set to the shaping die 40, the blow mechanism which blows a warm air or a hot air to the location where a drawdown phenomenon is easy to occur is provided.

  Accordingly, when the second embodiment is applied to the door trim upper 20 in the door trim 10, the door trim 10 is composed of an upper and lower divided body of the door trim upper 20 and the door trim lower 30, as shown in FIG. 9. For the foamed resin base material 21 that is lightweight and has an appropriate shape retaining property, the hollowed resin ribs 22 that have a reinforcing function on the back surface of the foamed resin base material 21, and the foamed resin base material 21. It is comprised from the three-layer laminated structure with the decorating material 23 laminated | stacked on the surface. Specifically, the decorating material 23 is composed of a two-layer laminated structure of a top layer 23a and a cushion layer 23b, and the hot melt film 25 for bonding the decorating material 23 and the foamed resin base material 21 is The foamed resin sheet S is laminated on one surface.

  Next, the outline of the manufacturing method of the door trim 10 in the second embodiment will be described with reference to FIG. 10. The hot melt film 25 is laminated on one surface of the foamed resin sheet S that is a material of the foamed resin base material 21. While being softened to a high temperature of 160 to 220 ° C. by the heater device 50, the decorative material 23 is not heated by the heater, or is kept at a low temperature heat treatment of 120 ° C. or lower even if the heat treatment is performed. deep. Then, when the molding upper mold 41 of the molding die 40 is raised, the foamed resin sheet S and the decorating material 23 are separately put into the mold 40 at predetermined positions. In the molding die 40 used in the second embodiment, a blow mechanism 70 is disposed at a predetermined position of the molding lower die 42. That is, a blow chamber 71 is provided in the molding lower mold 42, a blow hole 72 is opened from the blow chamber 71 to communicate with the mold surface of the lower mold 42, and an air supply pipe 73 is piped from the blow chamber 71. The air supply pipe 73 is connected to the blower 74, and the air supply pipe 73 is provided with an opening / closing valve 75.

  Accordingly, when the foamed resin sheet S that has been subjected to the high temperature treatment (the hot melt film 25 is laminated on one surface) is set on the mold surface of the molding lower mold 42, the foamed resin sheet S is in a high temperature state and is softened. Therefore, it shows a tendency to sag due to its own weight. However, since warm air or hot air is forcibly blown from the blow hole 72 toward the back surface side of the foamed resin sheet S, particularly in locations where it tends to sag, the foamed resin sheet S due to its own weight It is possible to prevent the so-called draw-down phenomenon, in which sags occur, as much as possible.

  The molding process after setting the foamed resin sheet S and the decorating material 23 is the same as in the first embodiment, and is omitted here. In the door trim upper 20 of the molded door trim 10, the foamed resin sheet is used. Since S was subjected to high temperature treatment, shrinkage strain does not remain inside the foamed resin base material 21, shrinkage deformation after molding can be eliminated, molding accuracy can be improved, and the molding die 40 of the foamed resin sheet S can be improved. By applying a blow pressure by a blow mechanism 70 to a predetermined location when the foamed resin sheet S is put in, a draw-down phenomenon of the foamed resin sheet S can be avoided and the thickness variation of the foamed resin sheet S can be eliminated. The plate thickness of 21 is substantially equal, and the molding accuracy can be improved by eliminating the thickness variation, as in the first embodiment. Use effect is obtained.

  In the second embodiment, a blow mechanism 70 is attached to the molding die 40 in order to eliminate the draw-down phenomenon of the foamed resin sheet S, and a member for suppressing the draw-down is provided on the foamed resin sheet S side. Although omitted, the case in which the first embodiment and the second embodiment are combined, that is, a structure in which the drawdown suppressing layer 24 such as a nonwoven fabric is integrated on one surface of the foamed resin sheet S, is further drawn down to the molding die 40. If the blow mechanism 70 that avoids the phenomenon is driven when the foamed resin sheet S is set, the draw-down phenomenon can be more effectively prevented.

  In the first embodiment and the second embodiment described above, the laminated structure according to the present invention is applied to the door trim upper 20 in the door trim 10 having the upper and lower split structures. However, the entire door trim 10 may be constituted by a laminated structure. In addition, if it is a laminated structure of foamed resin base material 21, resin rib 22, and decorating material 23, it is applied to all interior parts such as rear parcel shelf, floor trim, trunk trim, rear side trim, pillar garnish, and roof trim. be able to.

  Moreover, although the drawdown suppression layer 24, such as the nonwoven fabric used in Example 1, was applied to the surface facing the decorating material 23, it is also possible to laminate the opposite surface of the foamed resin sheet S. In addition to the non-woven fabric, the material for the draw-down suppressing layer 24 is not limited as long as it has a function of regulating the deformation of the foamed resin sheet.

1 is a front view showing a first embodiment in which the present invention is applied to a two-tone type automobile door trim. FIG. It is the II-II sectional view taken on the line in FIG. It is a front view which shows the resin rib and door trim lower of the door trim upper in the door trim for motor vehicles shown in FIG. It is a general view which shows the outline | summary of the manufacturing method of the door trim for motor vehicles shown in FIG. It is explanatory drawing which shows the lamination process of the foamed resin sheet and drawdown suppression layer which are used for the door trim upper in the door trim for motor vehicles shown in FIG. It is explanatory drawing which shows the setting process of the decorating material in the manufacturing method of the door trim for motor vehicles shown in FIG. 1, and a foamed resin sheet. 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 shown in FIG. 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 shown in FIG. It is sectional drawing which shows 2nd Example which applied this invention to the two-tone type vehicle door trim. It is explanatory drawing which shows the setting process of the decorating material in the manufacturing method of the door trim for motor vehicles shown in FIG. 9, and a foamed resin sheet. 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 shown in FIG. It is a front view which shows the conventional door trim. FIG. 13 is a sectional view taken along line XIII-XIII in FIG. 12. It is explanatory drawing which shows the shaping | molding method of the conventional door trim.

Explanation of symbols

10 Automotive Door Trims 16 Car Body Panels 20 Door Trim Upper (Laminated Structure)
21 Foamed resin base material 22 Resin rib 23 Decorating material 23a Top layer 23b Cushion layer 24 Drawdown suppression layer 25 Hot melt film 30 Door trim lower (single resin)
40 Molding mold 41 Molding upper mold 42 Molding lower mold 424 Groove (for resin rib molding)
425 Cavity (for door trim lower molding)
43a, 43b Injection machine 50 Heater device 60 Extruder 61, 62 Raw roll 63 Press roll 70 Blow mechanism 71 Blow chamber 72 Blow hole 73 Air supply pipe 74 Blower 75 Open / close valve S Foamed resin sheet M1, M2 Molten resin

Claims (3)

A foamed resin base material (21) which is molded into a required shape and is lightweight and has shape retention; and a resin rib (22) having a predetermined pattern shape laminated and integrated on the back surface of the foamed resin base material (21); In the automotive interior part (10) formed by adopting the laminated structure (20) composed of the decorating material (23) attached to the surface of the foamed resin base material (21) in whole or in part,
In the laminated structure (20), a drawdown suppression layer (24) is laminated on at least one surface of a foamed resin sheet (S) that is a material of the foamed resin base material (21), and heat softening treatment is performed at a high temperature. In a state where the sheet thickness of the foamed resin sheet (S) is maintained substantially constant by the drawdown suppression layer (24), the foamed resin sheet (S) is put into the molding die (41, 42), The decoration material (23) which abbreviate | omitted the heat processing to the upper surface or gave the low temperature heat processing is mounted, and it is by the residual heat of the said foamed resin sheet (S), and the mold clamping of a molding die (41, 42) An automotive interior part, wherein a decorative material (23) is integrated on the surface of a foamed resin substrate (21) with a low-pressure press. A foamed resin base material (21) which is molded into a required shape and is lightweight and has shape retention, and a resin rib (22) having a predetermined pattern shape laminated and integrated on the back surface of the foamed resin base material (21) A method for producing an automotive interior part (10), which employs a laminated structure (20) composed of a decorative material (23) attached to the surface of the foamed resin base material (21) as a whole or a part thereof. In
The foamed resin sheet (S) is heat-softened, and the heat-softened foamed resin sheet (S) and the decorative material (23) subjected to heat treatment or low-temperature heat treatment are molded into a mold ( 41, 42) and then blow mechanism (70) from the concave surface of the molded lower mold (42) where the draw-down phenomenon is likely to occur to the foamed resin sheet (S) toward the back side of the foamed resin sheet (S). After forcibly blowing hot air or hot air supplied from and suppressing the drawdown of the foamed resin sheet (S), the molds (41, 42) are then clamped together and press-molded at a low pressure, Resin ribs are obtained by injecting molten resin (M1) into the groove (424) of the molding lower mold (42) at any timing immediately before or after the mold clamping (41, 42). (22) Foamed resin substrate (21) Method of manufacturing automobile interior part, wherein the molding method of the laminated structure (20) for shaping the laminated structure by laminating integrally on the back side (20) is employed. The method for producing an automotive interior part according to claim 2, wherein a drawdown suppression layer (24) is laminated on at least one surface of the foamed resin sheet (S).

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