JP2010234688A - Joint structure of foamed resin molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve assembling accuracy by stabilizing a fastening position of a foamed resin molded article upon joining and integrating a resin molded article with the foamed resin molded article by fastening bosses. <P>SOLUTION: A luggage side trim 10 is assembled by joining and integrating a trim upper (resin molded article) 20 and a trim lower (foamed resin molded article) 30. A plurality of annular ribs 34, 35 are formed as protruding on a circumferential rim of an attachment hole 33 of the trim lower 30. By employing a support structure that butts the plurality of annular ribs 34, 35 to a reinforcing rib 22 face around a welding boss 21 in the trim upper 20, the fastening positions of the trim upper 20 and the trim lower 30 are stabilized, which enhances the assembling accuracy of the trim upper 20 and the trim lower 30. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a foamed resin that joins a foamed resin molded product molded by adopting a molding method in which the mold clearance of the mold is variable between the injection filling process and the foam molding process of the foamed resin material and the counterpart resin molded product. It relates to the joint structure of molded products, and in particular, resin molding by stabilizing the fastening position of the foamed resin molded product when inserting the fastening boss of the resin molded product into the mounting hole of the foamed resin molded product and fastening it. The present invention relates to a joint structure of a foamed resin molded product in which the assembly accuracy of the molded product and the foamed resin molded product is remarkably improved.

  FIG. 14 is a front view of the luggage side trim 1 mounted on the interior surface of the side wall panel of the luggage room of the vehicle. The luggage side trim 1 is formed by joining and fixing the upper and lower divided parts of the trim upper 2 and the trim lower 3. It is configured. In this conventional example, the trim upper 2 employs a resin molded product, and the trim lower 3 employs a foamed resin molded product. Then, as shown in FIG. 15, the trim upper 2 and the trim lower 3 are positioned so that the lower edge side of the trim upper 2 overlaps the surface side of the upper edge of the trim lower 3, and the trim upper 2 is positioned at the overlap portion. The boss 4 is erected on the back surface of the boss 4, the boss 4 is inserted into the mounting hole 5 of the trim lower 3, and the tip end of the boss 4 is subjected to fastening processing such as thermal welding or ultrasonic welding, and the trim upper 2 And the trim lower 3 are firmly joined and fixed.

  Next, a method for forming the trim upper 2 and the trim lower 3 will be briefly described. The trim upper 2 is molded into a required shape by injection-filling a thermoplastic resin material in a normal injection mold, but the molding die 6 shown in FIG. 16 is used for molding the trim lower 3. Yes. This molding die 6 is generally composed of a movable side die 7 and a fixed side die 8, and the movable side die 7 is opened with respect to the fixed side die 8 by driving of the drive cylinder 7a. Tightening is performed. As a supply system for supplying the foamed resin material M into the cavity C defined between the movable mold 7 and the fixed mold 8, an injection machine 8a is connected to the fixed mold 8. As a supply path for the foamed resin material M supplied from the injection machine 8a, the fixed mold 8 is provided with a hot runner 8b and a gate 8c. When the injection filling process of the foamed resin material M is completed, the movable side mold 7 is moved backward by a minute stroke to widen the mold clearance, and then the foamed resin material M is foam-molded to obtain the product surface. The molding of the trim lower 3 having the two-layer structure of the skin layer 3a and the inside of the foam layer 3b is completed.

  More specifically, with respect to the mounting hole 5 opened in the trim lower 3, as shown in FIG. 17, a cylindrical protrusion 7 b is erected on the movable mold 7, and the mold surface of the fixed mold 8 is provided on the mold surface. A recess 8d is provided for accommodating the tip of the cylindrical projection 7b. 17A shows the injection filling process of the foamed resin material M, FIG. 17B shows the foam molding process of keeping the mold clearance large, and the protrusion 7b is injection filled of the foamed resin material M. In the process, it is fully fitted in the recess 8d of the fixed mold 8, and when the movable mold 7 is moved backward, the recess 8d moves upward. In addition, as a conventional example of a manufacturing method of a foamed resin molded product that employs two processes of an injection filling process of the foamed resin material M and a foam molding process that ensures a large mold clearance, it is described in detail in Patent Document 1. Yes.

JP 2002-120252 A

  Thus, in the conventional molding method of the trim lower (foamed resin molded product) 3 in the luggage side trim 1, by adjusting the mold clearance between the movable side mold 7 and the fixed side mold 8, the accuracy can be improved. Good molding. That is, the foam clearance can be reduced and the foamed resin material M can be supplied into the cavity C in a state where foaming is suppressed, and the trim lower 3 can be accurately added to the final product shape by setting the mold clearance large during the foaming reaction. Can be molded.

  However, when opening the attachment hole 5 in the trim lower 3, as shown in FIG. 17 (b), the shape of the edge of the attachment hole 5 tends to sag at the corner, and in such a case, as shown in FIG. Thus, the shape droops easily around the mounting hole 5 in the range indicated by the symbol a in the figure, and when the boss 4 is fastened after the trim upper 2 and the trim lower 3 are positioned, the symbol b in the figure It has been pointed out that the fastening position is unstable and the assembling accuracy between the trim upper 2 and the trim lower 3 varies.

  The present invention has been made in view of such circumstances, and uses a molding die composed of a movable side mold and a fixed side mold that can be mutually opened and clamped, and injection filled with a foamed resin material. Structure of foamed resin molded product in which foamed resin molded product molded by adopting the molding method of foamed resin molded product with variable mold clearance between mold and foam molding process is joined with the other side resin molded product Therefore, it is possible to accurately shape the vicinity of the mounting hole, stabilize the fastening position with respect to the counterpart resin molded product, and provide a foamed resin molded product joint structure that enables accurate assembly. Objective.

  In order to achieve the above-mentioned object, the present invention provides a method in which a foamed resin material is injected and filled into a cavity defined between a movable mold and a fixed mold, and then the movable mold is moved backward. A welding boss that has a foaming space and is bonded to a foamed resin molded product formed by foaming into a required shape and a resin molded product molded into the required shape, and is erected on the back surface of the resin molded product Is inserted into the mounting hole of the foamed resin molded product, and then the welding boss fastening operation is performed. By forming a plurality of concentric annular ribs projecting from the hole as a base point, it is possible to accurately shape the vicinity of the mounting hole during foam molding of a foamed resin molded product. With foamed resin molded products At the time of positioning for bonding and fixing, the foam boss for the resin molded product is inserted by inserting the welding boss of the resin molded product into the mounting hole of the foamed resin molded product and bringing the annular rib around the mounting hole into contact with the back surface of the resin molded product. The fastening and fixing work of the welding boss is performed while the fastening position of the resin molded product is controlled to be constant.

  Here, the movable mold in the molding mold can be moved by a predetermined stroke by a cylinder or a press ram so that the mold can be opened and clamped with respect to the fixed mold, and in particular, an injection filling process of the foamed resin material A first mold position that secures a narrow mold clearance between the movable mold and the fixed mold, and a second mold that retracts the movable mold by a predetermined stroke from the first mold position to secure a foaming space. The stroke of the movable mold is set so as to include the mold positions.

  On the other hand, the fixed mold is provided with resin passages such as a hot runner and a gate in order to supply the foamed resin material into the cavity. And, in order to open the mounting hole in the foamed resin molded product, the movable side mold is formed with a cylindrical projection facing the fixed side mold side, and the shape and dimension of this projection are as follows: It is set according to the shape and size of the mounting hole established in the foamed resin molded product. A plurality of annular circumferential grooves are formed concentrically on the periphery of the protrusion, and as a result, a plurality of annular ribs are formed concentrically on the periphery of the mounting hole in the foamed resin molded product. Will be.

  Therefore, in the foam molding process in which the movable mold is retracted to secure the foaming space, the portion near the mounting hole of the foamed resin material semi-molded product is annularly formed in the plurality of circumferential grooves on the mold side. By fitting the rib, the mounting hole edge of the semi-molded product is pulled toward the movable mold following the retreating movement of the movable mold, avoiding the shape drooping at the corner of the mounting hole. Therefore, the shape can be accurately formed.

  Here, as a combination of the resin molded product and the foamed resin molded product, for example, a relatively large interior part mounted on the interior surface of the side wall panel of the vehicle such as a door trim, a rear side trim, a luggage side trim, It is applied to a structure that joins and fixes parts such as a trim upper and trim lower upper and lower parts, or a trim upper, trim center, trim lower, and other upper and lower parts. For example, the upper and lower parts of the trim upper and trim lower are taken as an example. Then, both ends are integrated by fastening the tip of the welding boss by caulking or the like. Also, when attaching the pocket back cover to the door trim body, the door trim body is made of foamed resin molded product, the pocket back cover is made of resin molded product, the pocket boss of the pocket back cover is inserted into the mounting hole of the door trim body, and the boss is fastened By processing, it can be applied to a form to be assembled.

  Further, in the joint structure of the foamed resin molded product according to the present invention, a boss is erected on the back surface of the resin molded product, and this boss may be either a welding boss or a screw-fixing boss. Then, the boss is inserted into the mounting hole of the foamed resin molded product, and the tip of the boss is fastened and fixed by welding caulking such as ultrasonic welding or heat welding, or by screws. At that time, at the edge of the mounting hole of the foamed resin molded product, a plurality of annular ribs are formed concentrically, and the tips of the plurality of annular ribs are in contact with the back surface of the resin molded product, so that the resin molding is always performed. The fastening position of the foamed resin molded product with respect to the product can be stabilized, and the assembly accuracy of both can be maintained well.

  As described above, according to the joint structure of the foamed resin molded product according to the present invention, a molding method for molding the foamed resin molded product by changing the mold clearance during injection filling and the mold clearance during the foaming reaction is adopted. In particular, by providing a plurality of annular circumferential grooves at the base periphery of the cylindrical protrusion provided to open the mounting hole in the foamed resin molded product, when the movable mold is retracted, it is in an unfoamed state. Since the mounting hole edge of the semi-molded product is made to follow the movement of the movable mold, the mounting hole edge can be shaped accurately, and in particular, resin molded products and foamed resin molded products When joining and integrating by fastening processing of the fastening boss, the end of the plurality of annular ribs provided around the mounting hole of the foamed resin molded product is brought into contact with the back surface of the resin molded product to stabilize the fastening position of both. A constant assembly accuracy. An effect that is.

It is a front view which shows the luggage side trim of the upper and lower divided structure to which the joining structure of the foamed resin molded product which concerns on this invention is applied. It is the II-II sectional view taken on the line in FIG. FIG. 3 is an enlarged cross-sectional view showing a joint structure between a trim upper and a trim lower shown in FIG. 2. It is explanatory drawing which shows the state at the time of insertion of the welding boss | hub in the joining structure of the trim upper shown in FIG. 2, and a trim lower. It is explanatory drawing which shows the state at the time of the welding boss fastening in the joining structure of the trim upper shown in FIG. 2, and a trim lower. It is explanatory drawing which shows another aspect at the time of the welding boss fastening in the joining structure of the trim upper shown in FIG. 2, and a trim lower. It is a schematic diagram which shows the structure of the shaping die used when shape | molding the trim lower in the luggage side trim shown in FIG. It is explanatory drawing which shows the structure of the location corresponding to the attachment hole vicinity part of the trim lower in the shaping die shown in FIG. It is explanatory drawing which shows the injection filling process of the foamed resin material in the molding method of the trim lower in the luggage side trim shown in FIG. It is explanatory drawing which shows the reverse operation state of the movable side metal mold | die in the molding method of the trim lower in the luggage side trim shown in FIG. It is explanatory drawing which shows the metal mold | die following state of the attachment hole vicinity part at the time of the retracting operation | movement of the movable mold shown in FIG. It is explanatory drawing which shows the foam molding process in the molding method of the trim lower in the luggage side trim shown in FIG. It is explanatory drawing which shows the state of the attachment hole vicinity part in the foam molding process shown in FIG. It is a front view which shows the conventional luggage side trim. It is the XV-XV sectional view taken on the line in FIG. It is explanatory drawing which shows the outline | summary of the shaping die used for shaping | molding of the trim lower in the conventional luggage side trim. It is explanatory drawing which shows the attachment hole vicinity part in the conventional molding die. It is explanatory drawing which shows the malfunction at the time of the fastening state of the conventional trim upper and trim lower.

  Hereinafter, embodiments of the joint structure for foamed resin molded products according to the present invention will be described in detail with reference to the accompanying drawings. Note that the gist of the present invention is as described in the scope of claims, and the contents of the embodiments described below are merely examples of the present invention.

  FIGS. 1 to 13 show an embodiment of the present invention, and FIG. 1 is a front view showing a luggage side trim having a vertically divided structure manufactured by applying a joint structure of foamed resin molded products according to the present invention. 2 and 3 are cross-sectional views showing the structure of the joint portion between the trim upper and the trim lower in the luggage side trim, and FIGS. 4 to 6 are explanations showing the joint structure between the trim upper and the trim lower in the luggage side trim. FIG. 7 is an explanatory diagram showing a schematic configuration of a molding die used when molding a trim lower in a luggage side trim, and FIG. 8 is an explanatory diagram showing a configuration of a portion near a mounting hole of the trim lower in the molding die. 9 to 13 are explanatory views showing respective steps of the trim lower forming method in the luggage side trim.

  In FIG. 1 to FIG. 3, the luggage side trim 10 is an interior part that is attached to the interior side of the side wall panel of the luggage room of the vehicle, and is composed of an upper and lower divided body of a trim upper 20 and a trim lower 30. Each of the trim upper 20 and the trim lower 30 has various functional parts such as a multi-functional hook for suspending equipment, an air grill for air conditioning, or a speaker grill separately from the trim upper 20 and the trim lower 30 or integrally. However, since it is not the gist of the present invention, these functional parts and their mounting structures are omitted here.

  By the way, as the material of the trim upper 20 and the trim lower 30 constituting the luggage side trim 10, a normal resin molded product employing an injection molding method is used as the trim upper 20. Synthetic resin materials that can be used as the material include polyethylene resins, polypropylene resins, polystyrene resins, polyethylene terephthalate resins, polyvinyl alcohol resins, vinyl chloride resins, polyamide resins, polyacetal resins, polycarbonate resins, ionomers. The resin is suitably selected from acrylonitrile resin, acrylonitrile / butadiene / styrene (ABS) resin, and the like.

  On the other hand, the trim lower 30 uses a foamed resin molded product, and the foamed resin molded product uses a foamed resin material in which a foaming agent is mixed in a synthetic resin material. For example, as the synthetic resin material that can be used, the resin material used for the trim upper 20 can be used, and the description thereof is omitted here. Moreover, as a foaming agent added with respect to a synthetic resin material, organic foaming agents, such as azodicarbonamide, and inorganic foaming agents, such as sodium bicarbonate, can be used.

  Next, based on FIG. 2 thru | or FIG. 6, the joining structure of the trim upper 20 and the trim lower 30 is demonstrated. That is, the present invention is characterized in that when the trim upper 20 and the trim lower 30 are joined, the fastening position of both can be stabilized to provide the luggage side trim 10 having excellent alignment accuracy. First, a welding boss 21 is erected on the rear surface of the trim upper 20, and a cross-shaped reinforcing rib 22 is integrated with the base of the welding boss 21. The trim lower 30 at a position corresponding to the welding boss 21 is provided with a mounting hole 33, and concentric annular ribs 34, 35 on the side facing the reinforcing rib 22 surface of the trim upper 20. Is provided as a double rib structure. As shown in FIG. 3, the annular ribs 34 and 35 have a rib width d1 of 1 to 1.5 mm, a distance d2 between the annular ribs 34 and 35 of 1 to 1.5 mm, and a rib height d3 of 1 mm. The corners R of the ribs 34 and 35 are set to 0.5 mm, respectively.

  Then, as shown in FIG. 4, in the state where the trim upper 20 and the trim lower 30 are positioned and the welding boss 21 is fastened, the annular ribs 34 and 35 erected on the periphery of the mounting hole 33 of the trim lower 30. The front end abuts against the reinforcing rib 22 surface of the trim upper 20, as shown in FIG. 5, the fastening position between the trim upper 20 and the trim lower 30 can always be stabilized, and is shown at the front end of the welding boss 21. As shown in FIG. 2, the trim upper 20 and the trim lower 30 can be firmly integrated by caulking with an ultrasonic machining horn that does not. Instead of ultrasonic welding, heat welding may be applied, and instead of the welding boss 21, a screw-fixing boss is adopted and a screw is fastened from the back surface side, thereby fastening the trim upper 20 and the trim lower. 30 can be joined and integrated.

  Further, as shown in FIG. 6, in the present invention, an inner annular rib 34 corresponding to the periphery of the attachment hole 33 and an outer annular rib 35 that is slightly larger on the outer side are provided at the periphery of the attachment hole 33 in the trim lower 30. For example, when the trim lower 30 is formed, even if a shape sag occurs on the inner annular rib 34, the tip of the outer annular rib 35 comes into contact with the reinforcing rib 22 of the trim upper 20, so that the predetermined position is obtained. The trim lower 30 can be positioned with high accuracy, and the alignment accuracy can always be kept good. In this embodiment, the double annular ribs 34 and 35 are provided on the periphery of the mounting hole 33 in the trim lower 30. However, the number of ribs can be increased or decreased within a range of 2 to 5 as desired. .

  In the present invention, a plurality of annular ribs 34 and 35 are provided on the periphery of the mounting hole 33 in the trim lower 30 to increase the alignment accuracy when the trim upper 20 and the trim lower 30 are assembled. 34 and 35 have an attendant effect of improving the molding performance when the trim lower 30 is molded.

  Next, FIGS. 7 and 8 show a schematic configuration of a molding die 40 used when molding the trim lower 30 in the luggage side trim 10. The molding die 40 includes a movable side die 50 and a fixed side. The mold 60 and the injection machine 70 are generally configured. More specifically, the movable mold 50 is driven by the press ram 51 so as to take three positions, namely, a mold opening position and a mold clamping position, as well as a foam molding position. On the other hand, the fixed side mold 60 is supplied with the foamed resin material M into the cavity C through the hot runner 61 and the gate 62 that serve as a resin passage for the foamed resin material M supplied from the injection machine 70, and foamed after molding. An ejector pin 63 for projecting the trim upper 20 that is a resin molded product is internally provided.

  Further, the trim lower 30 is formed along the shape of the cavity C defined between the movable mold 50 and the fixed mold 60. In order to form the mounting hole 33 opened in the trim lower 30, As shown in FIG. 8, a cylindrical protrusion 52 that matches the shape and size of the mounting hole 33 is formed at a predetermined position on the mold surface of the movable mold 50, and the base of the cylindrical protrusion 52 is formed. At the periphery, annular circumferential grooves 53 and 54 for forming annular ribs 34 and 35 in the attachment holes 33 of the trim lower 30 are recessed. Further, in order to receive the protrusion 52, a concave portion 64 is provided in the fixed mold 60.

  Next, a molding method capable of accurately molding the trim lower 30 which is a foamed resin molded product will be sequentially described with reference to FIGS. 9 to 13. First, as shown in FIG. 9, the movable mold 50 is clamped with respect to the fixed mold 60 by the press ram 51, and when in the mold clamping position, the cavity C is passed from the injector 70 through the hot runner 61 and the gate 62. The foamed resin material M is injected and filled inside. At this time, although not shown, it is also possible to adopt a counter pressure method in which air is forcibly introduced from the outside into the cavity C and the resin is filled in the cavity C so that the foamed resin material M does not undergo a foaming reaction.

  Next, when the injection filling process of the foamed resin material M is completed, as shown in FIG. 10, the movable side mold 50 moves backward by a minute stroke in the mold opening direction. In the backward movement of the movable mold 50, the unfoamed half-molded product P is accommodated in the cavity C, and a foaming space S corresponding to the backward stroke of the movable mold 50 is secured. Become. As shown in FIG. 11, the part corresponding to the mounting hole 33 of the trim lower 30 includes a part of the semi-molded product P in the annular circumferential grooves 53 and 54 provided at the base peripheral edge of the cylindrical protrusion 52. Therefore, the semi-molded product P does not sag in the corner portion in the vicinity of the mounting hole 33 by following the backward movement of the movable mold 50. Then, as shown in FIG. 12, in the non-foamed half-molded product P, the foam reaction is induced, and the trim lower 30 composed of the skin layer 31 and the foam layer 32 has a desired thickness in a space where the mold clearance is set large. Is formed. At this time, since the foamed resin material M enters the annular peripheral grooves 53 and 54 of the movable mold 50 and the annular ribs 34 and 35 are formed at the edge of the mounting hole 33 as shown in FIG. Thus, it is possible to perform molding with high accuracy along the cavity shape.

  As described above, according to the present invention, when the foamed resin molded product exemplified by the trim lower 30 is molded into a required shape, the edge of the mounting hole 33 does not sag and the shape can be accurately formed. In addition, with regard to the joint integration of the trim upper 20 and the trim lower 30, there is an effect that a stable fastening position between the two can be secured and the luggage side trim 10 with improved alignment accuracy can be formed.

  In the embodiment described above, the present invention is applied to the joint structure of the trim upper 20 that is a resin molded product and the trim lower 30 that is a foamed resin molded product in the upper and lower divided side trim 10. The application to be applied is not limited to this, and the present invention can be applied to the entire joining structure of a resin molded product and a foamed resin molded product. For example, in addition to the luggage side trim 10 composed of the trim upper 20 and the trim lower 30, a split back structure such as a door trim and a rear side trim, as well as a pocket back cover made of a resin molded product with respect to a door trim body made of a foamed resin molded product. It can also be applied to a structure in which the bosses are fastened and fixed together. Furthermore, it is also possible to employ a counter pressure method for supplying compressed air into the cavity C at the time of injection filling of the foamed resin material.

10 Luggage side trim 20 Trim upper (resin molded product)
21 welding bosses 22 reinforcing ribs 30 trim lower (foamed resin molded product)
31 Skin layer 32 Foam layer 33 Mounting hole 34, 35 Annular rib 40 Molding die 50 Movable side die 51 Press ram 52 Cylindrical protrusion 53, 54 Annular circumferential groove 60 Fixed side die 61 Hot runner 62 Gate 63 Ejector Pin 64 Recess 70 Injection machine C Cavity M Foamed resin material P Semi-molded product S Foaming space

Claims (1)

After the foamed resin material (M) is injected and filled into the cavity (C) defined between the movable mold (50) and the fixed mold (60), the movable mold (50) is retracted. By operating, a foaming space (S) is secured, and a foamed resin molded product (30) formed by foam molding into a required shape and a resin molded product (20) molded into the required shape are joined structures. After the welding boss (21) standing on the back surface of the resin molded product (20) is inserted into the mounting hole (33) of the foamed resin molded product (30), the welding boss (21) is fastened. In the joint structure of the foamed resin molded product (30),
A plurality of concentric annular ribs (34, 35) project from the mounting hole (33) on the side opposite the resin molded product (20) around the mounting hole (33) in the foamed resin molded product (30). By being formed, when the foamed resin molded product (30) is foam-molded, it is possible to accurately shape the vicinity of the mounting hole (33), while the resin molded product (20) and the foamed resin molded product ( 30), the welding boss (21) of the resin molded product (20) is inserted into the mounting hole (33) of the foamed resin molded product (30), and the ring around the periphery of the mounting hole (33) is positioned. By bringing the ribs (34, 35) into contact with the back surface of the resin molded product (20), the fastening position of the foamed resin molded product (30) with respect to the resin molded product (20) is controlled to be constant, and the welding boss ( 21) Fastening and fixing work is performed Junction structure of the resin foam product, characterized in that.

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