JP2005112245A - Interior trim part for automobile and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an interior trim part for an automobile and a method of manufacturing the interior trim part capable of reducing weight and cost and increasing molding properties by eliminating the occurrence of short shot and resin burrs. <P>SOLUTION: This interior trim part (door trim upper) 20 comprises a foam resin base material 21 reduced in weight and having shape retainability, a resin rib 22 formed integrally with the inner surface side thereof, and an inner seal mounting flange (resin flange) 24 formed at at least a part of the end edge portion of the outer peripheral edge of the foam resin base material 21. The light foam resin base material 21 is used and the projected areas of the resin rib 22 and the resin flange 24 are reduced to reduce the weight and cost. Also, dedicated gates 423a and 423c are set for the resin rib 22 and the resin flange 24 to eliminate the occurrence of the short shots of the resin flange 24 and resin burrs to increase the shape retainability and lower an injected capacity. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to automotive interior parts such as door trims, rear parcel shelves, floor trims, trunk trims, rear side trims and the like, and a method for manufacturing the same, and in particular, interior parts for automobiles that are lightweight and have excellent appearance design and formability. And a manufacturing method thereof.

  For example, the configuration of automobile interior parts will be described with reference to FIGS. 11 and 12 exemplifying a door trim. 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 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 is laminated on the back side of an elastomer sheet such as a TPO (thermoplastic olefin) sheet in consideration of environmental and recycling aspects. The laminated sheet material tends to be frequently used.

  Next, a conventional example of the method for forming the door trim 1 will be described with reference to FIG. First, a molding die 4 that molds the door trim 1 is connected to a molding upper die 5 that can move up and down by a predetermined stroke, a molding lower die 6 that forms a pair with the molding upper die 5, and a molding lower die 6. It is generally composed of the injection machine 7.

  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 upper molding die 5 up and down by a predetermined stroke, an elevating cylinder 5b is connected, and the molding lower die 6 is provided with a manifold 6b and a gate 6c that serve as a passage for molten resin from the injection machine 7.

  Further, in order to maintain an appropriate posture, the 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 upper and lower molds 5 and 6 are in the mold open state, the skin 3 is set in the mold, and then the upper and lower molds 5 and 6 are clamped and then injected into the product cavity between the two molds. By injecting and filling the molten resin M from the machine 7 through the manifold 6b and the gate 6c, the resin core material 2 is formed into a required curved shape, and the skin 3 is integrally formed on the surface of the resin core material 2 (for example, , See Patent Document 1).

  In FIG. 13, for convenience of explanation, the molten resin M is supplied to the mold surface of the core portion 6 a in an open state, but the molten resin M is injected and filled into the cavity after the mold upper and lower molds 5 and 6 are clamped. May be.

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

  However, in the conventional door trim 1, since the projected area of the resin core material 2 is large, there are problems that the material cost is high and the product is heavy.

  In addition, since the projected area of the resin core material 2 is large, it is necessary to set the injection pressure at the time of molding high, and a mold structure that can withstand the high injection pressure is required, and the cost of creating the mold increases. 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.

  In addition, since the flange 2a for attaching the inner seal provided at the waist portion of the door trim 1 is remote from the gate, molding defects such as short shots are likely to occur, and the injection pressure is increased to avoid this molding defect. In this case, resin burrs are likely to occur. Thus, the problem that it is difficult to maintain good molding accuracy when molding the inner seal mounting flange 2a is pointed out at the same time.

  The present invention has been made in view of such circumstances, can provide an automobile interior part that can promote weight reduction and reduce costs, and even if the injection pressure is set low to eliminate resin burrs, An object of the present invention is to provide an automotive interior part excellent in formability that does not cause molding defects such as short shots, and a method for producing the same.

  As a result of earnest research, the present inventors have given the function as a core material by imparting shape retention to the foamed resin sheet that has been used conventionally as the skin, and more. Compared to conventional resin cores with a large projected area, resin ribs with excellent rigidity are placed at locations where rigidity is required, that is, peripheral parts of products, panels, parts mounting locations, and parts where loads are applied. By providing an interior trim component that is lightweight and inexpensive, and in particular, by setting a dedicated gate on a resin flange provided along at least a portion of the outer peripheral edge of the interior trim component, It has been found that short shots can be avoided and the injection pressure can be set low, and the present invention has been related.

  That is, the automotive interior part according to the present invention is a lightweight and shape-retaining foamed resin base material, a resin rib laminated and integrated on the back surface of the foamed resin base material, and an outer surface of the foamed resin base material. An automotive interior part composed of a resin flange integrated on at least a part of the rear surface of the periphery, wherein the foamed resin base material is obtained by heat-softening a foamed resin sheet by clamping a molding die. The resin rib and the resin flange that are drawn into a required shape and integrated with the back surface of the foamed resin sheet are each provided with a dedicated gate.

  Here, the interior parts for automobiles can be applied to door trims, rear parcel shelves, floor trims, luggage trims, trunk trims, rear side trims, and the like.

  A foamed resin base material having shape retention can be obtained by molding after molding, even if there is no reinforcing material such as ribs, by molding the foamed resin sheet into a desired curved surface shape after heating and softening treatment. Even if it is removed from the mold, it has such rigidity (shape retention) that it retains its shape. Also, if the product shape includes a high expansion ratio part, after the foamed resin sheet is heat-softened, a vacuum suction mechanism is provided in the molding die and the foamed resin sheet is vacuumed along the inner surface of the molding die. A suction force may be applied.

  As the foamed resin sheet, a material obtained by adding a foaming agent to a thermoplastic resin is used. The thermoplastic resin may be one type of thermoplastic resin or two or more types of thermoplastic resins. Preferably, polyethylene resin, polypropylene resin, polystyrene resin, polyethylene terephthalate resin, polyvinyl alcohol resin, vinyl chloride resin, polyamide resin, polyacetal resin, polycarbonate resin, ionomer resin, acrylonitrile / butadiene / Styrene (ABS) resin or the like can be used.

  As the foaming agent, an organic foaming agent such as an azo compound, a sulfohydrazide compound, a nitroso compound or an azide compound, or an inorganic foaming agent such as sodium bicarbonate can be used.

  The foamed resin base material obtained by molding the foamed resin sheet into a required shape after heat softening treatment preferably has a foaming ratio of 2 to 10 times in consideration of the balance between the weight and strength of the product. The cell diameter of the foamed resin 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.

  Moreover, in order to improve external appearance designability, you may laminate | stack a decorating material on the surface of a foamed resin base material. As the decorating material, a woven fabric, a non-woven fabric, a knitted fabric, a sheet, a film, a foam, a net-like material, or the like can be used. Although the material which comprises these decorating materials is not specifically limited, It is more preferable to use the raw material which has air permeability, such as a woven fabric, a nonwoven fabric, and a knitted fabric, in order to utilize the sound absorption performance of a foamed resin base material.

  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, Acrylonitrile / butadiene / styrene (ABS) resin can be used.

  Moreover, you may mix various fillers in these thermoplastic resins. Examples of the filler that can be used include inorganic fibers such as glass fiber and carbon fiber, and inorganic particles such as talc, clay, silica, and calcium carbonate. Moreover, various additives, such as antioxidant, a ultraviolet absorber, a coloring agent, a flame retardant, and a low shrinkage agent, may be mix | blended.

  Furthermore, as the resin flange integrated with at least a part of the back surface of the edge portion of the foamed resin base material, for example, an inner seal mounting flange provided at the waist portion of the door trim, the front edge portion of the door trim, or the rear There are a front end, a rear end, and the like that are integrated with the edge.

  And according to the interior parts for automobiles according to the present invention, since the resin ribs are laminated and integrated in the sense of reinforcing the rigidity on the back side of the foamed resin base material having shape retention, the conventional product The resin core material over the entire back surface can be eliminated. 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-absorbing function of the foamed resin base material provides interior parts with excellent sound-absorbing performance. When polyolefin resin is used as the material for the foamed resin base material and resin rib, all-olefin resin is unified. Therefore, the separation process can be abolished and the recycling work can be simplified.

  Furthermore, since the molten resin is injected through the resin flange dedicated gate to the resin flange provided at a part of the edge of the foamed resin base material, it is possible to prevent a short shot and reduce the injection pressure. Resin flash does not occur.

  Next, a method for manufacturing an automotive interior part according to the present invention includes a foamed resin base material that is lightweight and has shape retention, and a resin rib and a resin flange that are laminated and integrated on the back surface of the foamed resin base material. In the automotive interior part manufacturing method, the foamed resin sheet, which is the material of the foamed resin base material, is heat-softened and then set in the molding die, and the molding die is clamped Forming the foamed resin sheet into the required shape by cooling the foamed resin sheet along the cavity shape of the molding die and then cooling the molded resin sheet, and the mold of the molding die At the same time as clamping or at the timing before mold clamping, the molten resin is supplied from the injection machine into the mold cavity through the resin rib gate and resin flange gate, and the resin rib and resin flange are released. Resin ribs integrated with the back surface of the resin base material, characterized in that comprising the molding step of the resin flange.

  Here, the mold is composed of a pair of split molds and an injection machine attached to one mold. 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. A resin rib gate is provided to supply molten resin to a groove (corresponding to the resin rib shape) drilled in the surface, and a recess (resin flange shape) drilled in the mold surface of the molded lower mold The resin flange gates are independently provided on the lower mold in order to supply the molten resin.

  Therefore, according to the method of the present invention, it is only necessary to mold the resin rib and the resin flange as compared with the conventional resin core material having a large projected area. The load on the mold can be reduced, and the amount of resin is small, saving material costs.

  Furthermore, since individual gates are set for the resin rib and the resin flange, conventionally, the resin can be smoothly supplied to the resin flange, which is likely to cause a short shot, and a molding defect such as a short shot is caused in advance. Can be prevented. Further, by setting the injection pressure small, it is possible to avoid the occurrence of resin burrs.

  Next, in a preferred embodiment of the present invention, in the resin rib and resin flange molding step, the resin rib gate opening time is delayed compared to the resin flange gate opening time, and the resin rib gate opening time is set. By shortening, the closing timing of both the gates is substantially synchronized.

  By controlling the opening time and opening time of the resin flange gate and the resin rib gate as described above, the gate opening time can be shortened compared to the conventional case.

  As described above, the automotive interior part according to the present invention is a lightweight and shape-retaining foamed resin base material, and a resin rib and a resin flange laminated and integrated on the back surface of the foamed resin base material. Since it is configured, the conventional heavy resin core material can be eliminated, and since it is lightweight, low-cost, and is a porous material, it has the effect of providing an automotive interior part with excellent sound absorption performance.

  Furthermore, the manufacturing method of the interior part for automobiles according to the present invention forms the foamed resin base material into a required shape along the cavity shape of the molding die, and at the same time, the resin rib and the resin flange on the back side of the foamed resin base material. If the process is integrated, the resin ribs and resin flanges, which are resin moldings, have a smaller projected area, so the load on the molding die is less than conventional resin cores and the cooling time is shortened. Can be In addition, when molding resin ribs and resin flanges, resin materials are supplied through dedicated gates respectively, so molding defects such as short shots and resin burrs can be prevented and moldability can be improved. It has the effect.

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

  FIG. 1 to FIG. 10 show a first embodiment in which the present invention is applied to a two-tone type automobile door trim and its manufacturing method, FIG. 1 is a front view showing the two-tone type automobile door trim, and FIG. FIG. 3 is a front view showing a resin rib, a resin flange and a door trim lower in which the foamed resin base material of the door trim upper in the door trim for the automobile is omitted, and FIGS. 4 to 6 show the manufacture of the door trim for the automobile. 4 shows a molding die used in the method, FIG. 4 is an overall view of the molding die, FIG. 5 is a plan view of a molding lower die in the molding die, and FIG. 6 shows a portion near the waist flange portion in the molding die. It is sectional drawing. FIG. 7 to FIG. 10 show the respective steps in the manufacturing method of the door trim for automobiles, FIG. 7 is a preheating step of the foamed resin sheet, FIG. 8 is a step of setting the foamed resin sheet in the mold, and FIG. Process, FIG. 10 is explanatory drawing which shows the formation process of a resin rib and a resin flange, respectively.

  1 and 2, a two-tone type automobile door trim 10 is composed of an upper and lower divided part 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 parts mounted on the door trim 10, an inside handle escutcheon 11 and a power window switch finisher 12 are attached to the door trim upper 20. The door trim lower 30 is provided with a door pocket opening 13, and on the back side thereof, as shown in FIG. 2, a pocket back cover (made of a resin molded body) 14 is attached. A speaker grill 15 is integrally formed on the side. Reference numeral 16 denotes a door panel.

  By the way, the door trim 10 for automobiles according to the present invention can apply the present invention to the structure of the door trim upper 20 which is a laminated structure to reduce the weight of the product, improve the moldability, and shorten the molding cycle. It is a feature.

  That is, the door trim upper 20 is formed into a desired curved surface shape and has a foamed resin base material 21 having shape retention, a resin rib 22 laminated and integrated on the back side of the foamed resin base material 21, and a foamed resin base material. The material 21 is generally composed of a decorating material 23 having a decorating function laminated on the surface side of the material 21 and an inner seal mounting flange 24.

  The foamed resin substrate 21 is heat-molded into a required shape after heat-softening the foamed resin sheet so as to have shape retention, for example, cold press-molded with a molding die having a desired mold surface. About the high expansion | deployment rate part, you may shape the foaming resin base material 21 by vacuum forming.

  The foamed resin sheet has a structure in which a foaming agent is added to a general-purpose thermoplastic resin. The thermoplastic resin includes a polyethylene resin, a polypropylene resin, a polystyrene resin, a polyethylene terephthalate resin, a polyvinyl alcohol resin, a chloride resin. Vinyl resin, polyamide resin, polyacetal resin, polycarbonate resin, ionomer resin, acrylonitrile / butadiene / styrene (ABS) resin, etc. can be used. As the foaming agent, organic foaming agents such as azodicarbonamide and bicarbonate An inorganic foaming agent such as sodium can be used. In this embodiment, a foamed resin sheet in which sodium bicarbonate is appropriately added as a foaming agent to a polypropylene resin is used. Moreover, the expansion ratio of the foamed resin base material 21 is set to 2 to 10 times, and the thickness is set to 0.5 to 30 mm, particularly preferably 1 to 10 mm.

  Next, 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 lattice pattern extending in the vertical and horizontal directions or in the oblique directions. The resin rib 22 is made of a general-purpose synthetic resin molded body, and as a synthetic resin that can be preferably used normally, a polyethylene resin, a polypropylene resin, a polystyrene resin, a polyethylene terephthalate resin, a polyvinyl alcohol resin, a vinyl chloride resin, A polyamide resin, a polyacetal resin, a polycarbonate resin, an ionomer resin, an acrylonitrile / butadiene / styrene (ABS) resin, or the like may be selected as appropriate. In the present embodiment, a polypropylene resin is considered 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 made of a laminated structure and the door trim lower 30 which is a single synthetic resin, and has an excellent appearance design due to an accent effect on the appearance. It has sex. 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, a decorative material 23 having a decorative property, and an inner seal attachment. Since the resin core material occupied over the entire surface of the product can be abolished and the lightweight foamed resin base material 21 is used, the resin rib 22 has a bone shape. The part where the load is applied, for example, the part excluding the clip seat, the upper surface of the waist part, the upper surface of the armrest part, etc. has a thinning structure, and the weight of the product is 40% or more compared to the conventional example The weight of the resin can be reduced, and the resin material can be saved significantly, which can contribute to cost reduction.

  Furthermore, since the foamed resin base material 21 has a porous structure, the door trim upper 20 has excellent sound absorption performance and can reduce noise inside and outside the vehicle interior. Further, in order to enhance the sound absorption performance of the foamed resin base material 21 for vehicle interior noise, the decorative material 23 laminated and integrated on the surface of the foamed resin base material 21 is made of woven fabric, non-woven fabric, knitted fabric or the like. A sheet material having air permeability is preferable. In addition to the breathable sheet such as woven fabric, non-woven fabric, and knitted fabric, the decorative material 23 is a synthetic resin sheet such as a vinyl chloride sheet or a TPO (thermoplastic olefin) sheet (recyclable if a TPO sheet is used), Synthetic resin films, foams, nets and the like can be used. In addition, as a low-cost configuration, the decorating material 23 may be omitted, and the surface of the foamed resin base material 21 may be subjected to painting or printing processing.

  Then, as will be described in detail in a method for manufacturing the door trim 10 described later, the foamed resin base material 21 is press-molded into a required shape after heat-softening the foamed resin sheet, and then the resin in the same molding die. The rib 22 and the inner seal mounting flange 24 are injection-molded. In particular, as shown in FIGS. 2 and 3, the inner seal mounting flange 24 does not generate short shots or resin burrs, and is high. Formability is obtained and the appearance performance of the waist part is maintained well.

  Next, a method for manufacturing the door trim 10 shown in FIGS. 1 to 3 will be described below. First, based on FIG. 4 thru | or FIG. 6, the structure of the shaping die 40 is demonstrated. In FIG. 5, a molding die 40 used for molding the door trim 10 includes a molding upper mold 41 that can move up and down by a predetermined stroke, a molding lower mold 42 that is paired with the molding upper mold 41, and a molding lower mold 42. It consists of two injection machines 43a and 43b connected to each other.

  More specifically, the molding upper die 41 has a cavity portion 411 that matches the product shape, and is driven up and down by a predetermined stroke by an elevating cylinder 412 connected to the upper surface of the molding upper die 41. In addition, guide bushes 413 serving as a guide mechanism are provided at the four corners of the molding upper die 41.

  On the other hand, the molding lower die 42 is provided with a core portion 421 corresponding to the cavity portion 411 of the molding upper die 41. In addition, manifolds 422a and 422b and gates 423a, 423b, and 423c are provided to supply molten resin to the mold surface of the core portion 421, and resin passages of the manifolds 422a and 422b and gates 423a, 423b, and 423c are provided. Then, molten resins M1 and M2 supplied from the injection machines 43a and 43b are supplied to the upper surface of the core portion 421.

  In the present invention, as shown in FIGS. 5 and 6, a groove 424 for molding the resin rib 22 is formed in the molding lower mold 42 corresponding to the door trim upper 20, and a molten resin is formed in the groove 424. In order to supply M1, a resin rib gate 423a (indicated by G1 to G4 and G7 in FIG. 5) is provided. On the other hand, also in the recess 425 for forming the inner seal mounting flange 24, resin flange gates 423c (indicated by G5 and G6 in FIG. 5) independent from the resin rib gate 423a are provided at two positions on the left and right. . In order to form the resin rib 22 and the inner seal mounting flange 24, a groove 424 and a recess 425 to which the molten resin M1 is supplied are formed on the upper surface of the core 421, while the door trim lower 30 is formed. In addition, a cavity 426 having a predetermined clearance is set between the upper and lower molds 41 and 42.

  In addition, guide posts 427 serving as a guide mechanism protrude from the four corners of the lower molding die 42. The guide posts 427 are guided into the guide bush 413 when the molding upper and lower dies 41 and 42 are clamped. As a result, the pressing posture of the molding upper die 41 can be properly maintained.

  Hereinafter, a method for manufacturing the door trim 10 will be described. First, as shown in FIG. 7, the heater device 50 heats and softens the laminate of the decorating material 23 on one surface of the foamed resin sheet S to a predetermined temperature. In this embodiment, a polypropylene foam sheet (manufactured by Sumika Plustech, trade name: Sumiceller foam PP sheet, expansion ratio = 3 times, thickness 3 mm) is used as the foam resin sheet S.

  Next, as shown in FIG. 8, the foamed resin sheet S (laminated with the decorating material 23) subjected to heat softening is applied to the cavity portion 411 of the molding upper mold 41 and the core of the molding lower mold 42 at the location corresponding to the door trim upper 20. Set in the upper half of the cavity defined by section 421.

  Then, after setting the foamed resin sheet S, as shown in FIG. 9, the lifting cylinder 412 of the molding upper die 41 is operated, the molding upper die 41 is lowered by a predetermined stroke, and the molding upper and lower dies 41, 42 are molds. The foamed resin sheet S is shaped and cooled along the cavity shape, and the foamed resin base material 21 is formed into a required shape. When the foamed resin base material 21 is molded, the resin rib 22 and the inner seal mounting flange 24 are integrated. That is, the molten resin M1 is injected and filled into the groove portion 424 of the lower molding die 42 through the manifold 422a and the gate 423a from the first injection machine 43a to form the resin rib 22, and the molten resin into the recess 425 from the gate 423c. M1 is injected and filled, and the inner seal mounting flange 24 is formed. The resin rib 22 and the inner seal mounting flange 24 are connected after the molten resin M1 is filled. Further, as described above, the injection timing of the molten resin M1 may be performed after the mold upper and lower molds 41 and 42 are clamped, but may be set before the mold upper and lower molds 41 and 42 are clamped.

  At the same time, in order to mold the door trim lower 30, the molten resin M2 is injected and filled into the cavity 426 through the manifold 422b and the gate 423b from the second injection machine 43b, and the door trim lower 30 is molded into a required shape. In addition, as this molten resin M1 and M2, fillers, such as a talc, are mixed in an appropriate ratio with Sumitomo Noblen BUE81E6 (a polypropylene made by Sumitomo Chemical Co., Ltd., melt index = 80 g / 10 min).

  Accordingly, the molten resin M1 is injected and filled from the first injection machine 43a into the groove 424 and the recess 425, while the molten resin M2 of the second injection machine 43b is injected and filled into the cavity 426, so that the door trim upper 20 The resin rib 22 and the inner seal mounting flange 24 are formed into required shapes, and the door trim lower 30 is integrally formed with the door trim upper 20.

  Here, the gate balance (open delay time, open time) of the resin rib gate 423a and the resin flange gate 423c is shown in Table 1.

  The locations of the gates G1 to G7 in Table 1 are shown in FIG.

  As is apparent from Table 1, with respect to G5 and G6, which are resin flange gates 423c, resin is injected from G6 simultaneously with mold clamping, and resin is filled into the recesses 425 from G5 with a delay of 1 second. .

  Further, for the resin rib gate 423a, the resin is injected from G1, G2 with a delay of 3 seconds, G2 with a delay of 4 seconds, and G3, G4, G7 with a delay of 6 seconds. Thus, the opening time (open delay time) of the resin flange gate 423c and the resin rib gate 423a is controlled, and the opening time is determined by the resin flange gate 423c for supplying the recess 425 having a large resin capacity. For G5 and G6, 15 seconds and 17 seconds, respectively, and for G1, G4 and G7 which are gates 423a for resin ribs to be supplied to the groove portion 424 having a relatively small resin capacity, the opening time is relatively short. Is set.

  Therefore, since the resin flange gate 423c is specially set, the short shot can be avoided and the injection pressure is small for the resin flange that easily induces molding defects such as the short shot such as the inner seal mounting flange 24. Therefore, the generation of resin burrs can be prevented.

  The opening time of the gates 423a and 423c is also 17 seconds at the maximum, and the closing time of the gates 423a and 423c is almost synchronized, so that the gate opening time as a total can be shortened. There is an advantage that shortening can be achieved. In the embodiment described above, the mold opening direction of the molding die 40 is set in the vertical direction, but the mold opening direction may be set in the horizontal direction.

  The embodiment described above is applied to the door trim upper 20 in the two-tone type automobile door trim 10. However, the embodiment can also be applied to an integrated door trim, and a rear parcel shelf as an interior part other than the door trim 10. It can be applied to all interior parts such as trunk trim and rear side trim.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view showing a two-tone type automobile door trim that is an embodiment of an automobile interior part according to the present invention. It is the II-II sectional view taken on the line in FIG. It is a front view which shows the resin rib which abbreviate | omitted the foamed resin base material in the door trim for motor vehicles shown in FIG. 1, the resin flange, and the door trim lower. It is a side view which shows the outline | summary of the shaping die used for manufacture of the door trim shown in FIG. It is a top view which shows the shaping | molding lower die in the shaping die shown in FIG. It is sectional drawing which shows the waist flange part in the molding die shown in FIG. It is explanatory drawing which shows the preheating process of the foamed resin sheet in the manufacturing method of the door trim shown in FIG. It is explanatory drawing which shows the in-mold setting process of the foamed resin sheet in the manufacturing method of the door trim shown in FIG. It is explanatory drawing which shows the formation process of the foamed resin base material in the manufacturing method of the door trim shown in FIG. It is explanatory drawing which shows the formation process of the resin rib and the resin flange in the manufacturing method of the door trim shown in FIG. It is a front view which shows the conventional door trim. FIG. 12 is a sectional view taken along line XII-XII in FIG. 11. It is a schematic diagram of the molding die used for the manufacturing method of the conventional door trim.

Explanation of symbols

10 Two-tone type automobile door trim 20 Door trim upper 21 Foamed resin base material 22 Resin rib 23 Decorating material 24 Inner seal mounting flange (resin flange)
30 door trim lower 40 molding die 41 molding upper mold 42 molding lower mold 43 (43a, 43b) injection machine 423a resin rib gate 423b door trim lower molding gate 423c resin flange gate 424 groove 425 recess 426 cavity 50 heater device S foam Resin sheet M1, M2 Molten resin

Claims (3)

A foamed resin base material (21) that is lightweight and has shape retention, a resin rib (22) laminated and integrated on the back surface of the foamed resin base material (21), and an outside of the foamed resin base material (21) An automotive interior part (20) composed of a resin flange (24) integrated with at least a part of the rear surface of the periphery,
The foamed resin base material (21) is formed by drawing the heat-softened foamed resin sheet (S) into a required shape by clamping the molding dies (41, 42), and the back surface of the foamed resin sheet (S). A resin rib (22) and a resin flange (24) integrated with each other are provided with dedicated gates (423a, 423c), respectively. For automobiles comprising a foamed resin base material (21) that is lightweight and has shape retention, and a resin rib (22) and a resin flange (24) that are laminated and integrated on the back surface of the foamed resin base material (21). In the manufacturing method of the interior part (20),
A step of setting the foamed resin sheet (S) to be set in the molding die (41, 42) after the heat-softening treatment of the foamed resin sheet (S) which is the material of the foamed resin base material (21);
After the molding die (41, 42) is clamped, the foamed resin sheet (S) is shaped according to the cavity shape of the molding die (41, 42) and then cooled to cool the foamed resin base material ( 21) forming a foamed resin substrate (21) into a required shape;
At the same time as or before the mold clamping of the molding dies (41, 42), the molten resin (M1) is transferred from the injection machine (43a) to the resin rib gate (423a) and the resin flange gate (423c). The resin rib (22) and the resin flange (22) are integrated into the back surface of the foamed resin base material (21). 24) the molding process;
A method for producing an interior part for an automobile, comprising: In the molding process of the resin rib (22) and the resin flange (24), the opening timing of the resin rib gate (423a) is delayed compared to the opening timing of the resin flange gate (423c), and the resin rib gate (423a) 3) The method for manufacturing an interior part for an automobile according to claim 2, wherein the closing time of both the gates (423a, 423c) is substantially synchronized by shortening the opening time.

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