JP2010105352A - Vibration-welded structure of resin molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the rattling of a reinforcement member and to promote the rigidity securing and weight reduction of a whole resin molding. <P>SOLUTION: A hard, thin-walled solid layer 25 with high resin density is formed on the front and back surfaces of a panel body 21 of a front panel 17, and a foamed layer 27 which is sandwiched by the solid layer 25 and has a large number of voids inside is formed in the panel body 21. Between the front side panel 17 and a rear panel 19, the long, resin-made reinforcement member 20 is held to stretch in the vibration direction X during vibration welding. A first long welding rib 47 made of a solid is integrally protruded along the reinforcement member 20 on the upper surface 20a of the reinforcement member 20 on the front panel 17 side. The front end of the first welding rib 47 is made to penetrate the solid layer 25 on the back side of the panel body 21 of the front panel 17 to intrude into the foamed layer 27 during vibration welding so that the foamed layer 27 and the solid layer 25 are welded together and unified. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an improvement in a vibration welded structure of a resin molded product obtained by fusing and integrating a resin first panel and a resin second panel in a state where they are pressed against each other.

  Patent Document 1 discloses a vibration welded structure of a resin molded product in which a resin first panel and a resin second panel are vibration welded by welding ribs protruding from the second panel.

Patent Document 2 discloses a vibration welded structure of a resin molded product in which a first resin panel and a second resin panel are vibration welded with a reinforcing member interposed between the two panels. Yes.
JP 2004-58468 A Japanese Patent Laid-Open No. 10-80982

  However, in Patent Document 1, the rigidity of the resin molded product may be insufficient depending on the structure of the resin molded product, the number of welding ribs, and the like.

  Moreover, in the said patent document 2, although both panels are reinforced with a reinforcement member, since the reinforcement member is not welded to any of the 1st panel and the 2nd panel, and it is only pinched | interposed, clamping force is Depending on the shape of the panel, the reinforcing member may rattle between the two panels.

  Moreover, since the 1st panel and 2nd panel of both said patent documents 1, 2 are panels which consist only of a solid layer, weight increases and it is unpreferable from a viewpoint of the weight reduction of a resin molded product.

  This invention is made | formed in view of this point, The place made into the objective is to promote the rigidity ensuring and weight reduction of the whole resin molded product while preventing the rattling of a reinforcement member.

  In order to achieve the above object, according to the present invention, at least one of the two panels has a foamed layer inside, and protrudes from a reinforcing member interposed between the one panel and the other panel. The weld rib is welded to the one panel.

  Specifically, the present invention is directed to a vibration welded structure of a resin molded product that is integrally welded by vibrating in a state where the first resin panel and the second resin panel are in pressure contact with each other. I took the right solution.

  In other words, the invention according to claim 1 is that the first panel includes a thin solid layer formed on the front and back surfaces, and a foam layer sandwiched between the solid layers and having a large number of voids inside. A long resin reinforcing member is sandwiched between the first panel and the second panel so as to extend in the vibration direction at the time of vibration welding, and on the first panel side of the reinforcing member, In addition, a long first welding rib made of solid is integrally projected along the reinforcing member, and the front end portion of the first welding rib is a solid layer on the back side of the panel body of the first panel during vibration welding. It penetrates and penetrates into the foamed layer, and is characterized by being fused and integrated with the foamed layer and the solid layer.

  According to a second aspect of the present invention, in the vibration welded structure of the resin molded product according to the first aspect, the long panel-side weld rib made of solid is vibrated during vibration welding on the back surface of the second panel. The front end of the panel-side weld rib penetrates the solid layer on the back side of the panel body of the first panel and penetrates into the foam layer during vibration welding. The foam layer and the solid layer are welded and integrated.

  According to a third aspect of the present invention, in the vibration welded structure of the resin molded product according to the first or second aspect, the second panel includes a thin solid layer formed on the front and back surfaces, and a solid layer. A panel main body having a foam layer sandwiched between and having a large number of voids inside is provided, and on the second panel side of the reinforcing member, a long second welding rib made of solid follows the reinforcing member. The front end of the second weld rib penetrates the solid layer on the back side of the panel body of the second panel and penetrates into the foam layer during vibration welding, and is integrated with the foam layer and the solid layer. It is characterized by.

  According to the first aspect of the present invention, since the reinforcing member and the first panel are welded to each other by the first welding rib, rattling of the reinforcing member is prevented. In addition, the tip of the first weld rib of the reinforcing member penetrates into the foam layer of the first panel and is welded and integrated not only with the solid layer on the back side of the panel body but also with the foam layer. Compared with the case where it did, the welding area becomes large and high welding strength is obtained. As a result, the coupling state between the reinforcing member and the first panel is strengthened, rattling of the first welding rib is prevented, and the rigidity of the entire resin molded product can be ensured.

  Furthermore, since the inside of the panel body of the first panel is formed of a foam layer, the weight of the resin molded product is reduced (weight reduction) compared to the case where the first panel is formed of only a solid layer, and the resin Material costs are reduced.

  According to the invention of claim 2, the panel side welding rib tip of the second panel penetrates not only to the panel main body back side solid layer of the first panel but also to the foam layer, like the first welding rib. Since the foamed layer is also welded and integrated, the bonded state of the first panel and the second panel is stronger and more reliably stabilized than in the first aspect, and the rigidity of the entire resin molded product is further increased.

  According to the third aspect of the invention, since the reinforcing member is also welded to the second panel by the second welding rib, rattling of the reinforcing member is more reliably prevented. Also in this case, the second welding rib tip of the reinforcing member penetrates into the foam layer of the second panel and is welded and integrated not only with the solid body back side solid layer of the second panel but also with the foam layer. Therefore, the coupling state of the reinforcing member and the second panel becomes more and more firm and reliable, and the rigidity of the entire resin molded product is further increased.

  Moreover, since the inside of a panel main body is also comprised by the foam layer in the 2nd panel, reduction of the weight of a resin molded product and reduction of the resin material cost are further achieved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a perspective view showing a rear luggage compartment 3 of the automobile 1, and FIG. 2 is a cross-sectional view taken along the line AA of FIG.

  The rear luggage compartment 3 is located behind the rear seat 7 of the automobile 1, and resin trunk side trims 9 are disposed on both sides in the vehicle width direction of the rear luggage compartment 3 so as to cover the vehicle body panel 11. A plate-like floor board 5 as a resin molded product according to Embodiment 1 of the present invention is detachably attached to the rear of the rear cargo room 3 behind the tire house 13. A concave storage portion 15 for storing a tire or the like is formed.

  As shown in FIGS. 3 to 5, the floor board 5 includes a resin front side panel 17 as a first panel and a resin back side panel 19 as a second panel. It is comprised by welding integrated by making it. Further, between the front side panel 17 and the back side panel 19, a long resin reinforcing member 20 having a substantially square pipe shape as shown in FIG. 6 is provided in the vibration direction (direction of FIG. 3X) during vibration welding. The panel is sandwiched so as to extend. In FIG. 2, the floor board 5 is simply shown as a cross-sectional view composed of a single panel for the sake of space.

  The front panel 17 is formed integrally with the panel main body 21 that extends substantially flat and forms the main body of the front panel 17 and the peripheral edge 21a of the panel main body 21 over the entire circumference, and projects toward the back panel 19 side. And a substantially rectangular annular peripheral wall portion 23. A recess S <b> 1 is formed inside the peripheral wall portion 23. The panel body 21 of the front panel 17 has a thin solid layer 25 having a high resin density formed on the front and back surfaces and a large number of voids sandwiched between the solid layers 25. And a foam layer 27 having a low resin density. Further, the peripheral edge portion 21 a of the panel body 21 is constituted by a solid layer thicker than the solid layer 25, and the peripheral wall portion 23 is also constituted only by a solid layer thicker than the solid layer 25. In addition, a skin 29 made of a nonwoven fabric or the like is integrally attached to the surface of the panel main body 21 and the peripheral wall portion 23 of the front side panel 17 from the viewpoint of improving the appearance and the vehicle width in the vicinity of the rear side edge of the vehicle body. A holding recess 31 (shown in FIG. 3) is formed in the center of the direction.

  Similar to the front panel 17, the back panel 19 is formed integrally with the panel body 33, which extends substantially flat and forms the main body of the back panel 19, and the peripheral edge 33a of the panel body 33 over the entire circumference. And a peripheral wall portion 35 protruding toward the panel 17 side. A recess S <b> 2 is formed inside the peripheral wall portion 35. The panel body 33 of the back side panel 19 has a thin resin layer 37 having a high resin density and is formed on the front and back surfaces, and a large number of voids inside the solid layer 37. And a foam layer 39 having a low resin density. Further, the peripheral edge portion 33 a of the panel main body 33 is constituted by a solid layer thicker than the solid layer 37, and the peripheral wall portion 35 is constituted only by a solid layer thicker than the solid layer 37. Further, on the back side of the panel body 33 of the back side panel 19 (the back side solid layer 37 facing the front side panel 17), the five plate-like panel-side welding ribs 41a to 41e made of solid extend in the vibration direction X, respectively. They are integrally projected in parallel from the front side of the vehicle body. The front half of these panel-side welding ribs 41 a to 41 e protrudes closer to the front panel 17 than the protruding surface of the peripheral wall portion 35. In addition, the reinforcing ribs 44 whose plate surfaces are orthogonal to the vibration direction X are provided on the panel side welding ribs 41a to 41e so that the panel side welding ribs 41a to 41e do not bend in the direction orthogonal to the vibration direction X during vibration welding. It is integrally formed on both sides and stably supports these welding ribs 41a to 41e. A plurality of reinforcing ribs 44 are formed at intervals in the longitudinal direction of the panel-side welding ribs 41a to 41e, and are formed in a triangular plate shape so that the protruding height gradually decreases with increasing distance from the tip side of the welding ribs 41a to 41e. Is formed.

As shown in FIG. 7, plate-like reinforcing ribs 43 are provided on the rear side of the vehicle body (the third panel from the front of the vehicle body) on the reinforcing ribs 44 near the longitudinal ends of the second panel side welding rib 41b from the front of the vehicle body. It is extended integrally in the state protruded by the panel main body 33 back so that it may go to the side welding rib 41c). Further, the plate-like reinforcing rib 43 is also provided on the front side of the vehicle body (the panel-side welding rib 41b) on the reinforcing rib 44 of the third panel-side welding rib 41c from the front of the vehicle body facing the reinforcing rib 43 of the panel-side welding rib 41b. ) So as to project toward the rear surface of the panel body 33 so as to extend integrally therewith. Protruding end 43a of the tip of the two reinforcing ribs 43 face each other so as to have a gap L _1, both protruded end 43a is formed so as to be fitted into the engagement groove 49 described later (see FIG. 6). On both side plate surfaces near the protruding end 43a of the reinforcing rib 43, rectangular plate-like cross ribs 46 are integrally protruded so that the plate surface is along the vibration direction X, and the protruding end 43a of the reinforcing rib 43 is the cross rib. It is formed so as to protrude from 46 so as to face each other. Gap between the pair of cross ribs 46 L ₂ is slightly larger than the width in the direction perpendicular to the vibration direction X of the reinforcing member 20.

  As shown in FIG. 6, the reinforcing member 20 is formed in a substantially rectangular pipe shape having an elongated shape with a top surface portion 20 a extending in the longitudinal direction, a pair of side surface portions 20 b and 20 c, and a bottom surface portion 20 d and having a hollow portion 20 e. Yes. On the upper surface portion 20a side of the reinforcing member 20, a long first welding rib 47 made of solid protrudes continuously and integrally along the reinforcing member 20 from one end to the other end in the longitudinal direction. Has been. Further, in the vicinity of and in the middle of both ends in the longitudinal direction (vibration direction X) of the side portions 20b and 20c, an engaging groove 49 extending in the vertical direction corresponds to the reinforcing rib 43 of the back panel 19 and the protruding of the reinforcing rib 43. The end 43a is formed so that it can be fitted. The lower surface portion 20d is formed flat. In FIG. 6, the intermediate engagement groove 49 is not shown for the sake of space.

  The surface of the lower surface portion 20d of the reinforcing member 20 is in contact with the back surface of the panel main body 33 between the panel side welding ribs 41b and 41c in the back side panel 19, and the protruding end 43a of the reinforcing rib 43 of the back side panel 19 is associated with the reinforcing member 20. In a state where the reinforcing member 20 is positioned with respect to the back side panel 19 by being fitted into the mating groove 49, the front side panel 17 and the back side panel 19 are vibrated and integrated with the recesses S1 and S2 facing each other. The floor board 5 is configured.

  In the floor board 5 assembled in this way, the upper surface portion 20a of the reinforcing member is positioned on the front panel side, and the front end portion of the first welding rib 47 penetrates the panel main body 21 rear surface side solid layer 25 of the front side panel 17 and foams. The foam layer 27 penetrates into the layer 27 and the foam layer 27 around the tip of the first weld rib 47 is covered with the solid portion 45 melted and solidified to be integrated with the foam layer 27 and the solid layer 25 on the back side of the panel body 21. Then, the surface of the upper surface portion 20a of the reinforcing member 20 and the rear surface of the panel body 21 of the front side panel 17 approach each other by the intrusion dimension of the first welding rib 47, and the first welding rib 47 between the reinforcing member 20 and the front side panel 17 is brought close. , That is, the corresponding length between the surface of the upper surface portion 20a of the reinforcing member 20 and the back surface of the panel body 21 of the front panel 17 is shortened.

  Moreover, the front-end | tip part of panel side welding rib 41a-41e pierces the panel main body 21 back surface side solid layer 25 of the front side panel 17, and penetrates into the foam layer 27, and the foam layer 27 around the front-end | tip part of panel side welding rib 41a-41e becomes. It is covered with a solid portion 45 that has been melted and solidified, and is integrated with the foam layer 27 and the solid layer 25 on the back side of the panel body 21 by welding. The penetration dimensions of the panel-side welding ribs 41a to 41e are equal to the penetration dimension of the first welding rib 47, and the panel main bodies 21 and 33 of the panels 17 and 19 approach each other by this penetration dimension. The length of the panel side welding ribs 41a to 41e between the nineteens, that is, the length corresponding to the back surface of both panels 17 and 19 among the total length of the panel side welding ribs 41a to 41e is shortened. Further, the peripheral wall portion 23 of the front side panel 17 and the peripheral wall portion 35 of the back side panel 19 are close to each other to form a gap S3. Further, the thickness direction side surface 19a of the back side panel 19 is positioned so as to have a predetermined width over the entire circumference inside the thickness direction side surface 17a of the front side panel 17, and the back side panel 19 is located in the recess S1 of the front side panel 17, that is, The inner part is covered rather than the surrounding wall part 23 of the panel main body 21 back surface.

  Next, a method for manufacturing the floor board 5 configured as described above will be described. First, the front side panel 17, the back side panel 19, and the reinforcing member 20 are each formed. The front side panel 17 is shape | molded as follows, for example.

  At the time of molding, a mold (not shown), a thermoplastic resin (for example, polypropylene), and a skin 29 are prepared. The forming mold forms a first mold as a fixed mold that molds the front side including the peripheral edge portion 21a of the front panel 17, a second mold as a slide mold corresponding to the recess S1, and a protruding end surface of the peripheral wall 23. And a third mold as a movable mold, and the second mold is disposed in the third mold so as to be able to advance and retreat. The thermoplastic resin is a mixture of foaming promoting substances such as a chemical foaming material that generates gas by a chemical reaction and an inert gas (physical foaming material) such as carbon dioxide gas and nitrogen gas. However, it is also possible to use a glass fiber or other fiber mixed therein.

  First, with the skin 29 set on the molding surface of the first mold and the mold closed, the molten thermoplastic resin is injected and filled into the cavity of the mold from the injection machine. At this time, the distance between the first mold and the second mold is preferably set to approximately ½ or more of the thickness of the panel body 21. Thereafter, the thermoplastic resin in the vicinity of the molding surface of the mold begins to solidify early due to the mold temperature. At this point, the second mold is fixed to the panel body 21 while the distance between the first mold and the third mold is fixed. The cavity volume is increased by sliding away from the first mold in the mold opening direction (retracting direction) so as to have a thickness. Then, due to the volume expansion of the cavity, the thermoplastic resin that has been compressed between the first mold and the second mold so far (the expansion is restricted) is pulled to the second mold and the chemical reaction in the thermoplastic resin. It expands and expands due to the gas generated by the gas or an inert gas. When fibers such as glass fiber are mixed in the thermoplastic resin, the compression is reduced and the fiber is elastically restored, and the thermoplastic resin is also restored by this elastic restoring force (springback phenomenon). Expands. As a result, the peripheral wall portion 23 and the panel body 21 are molded. The peripheral wall portion 23, the peripheral edge portion 21a of the panel main body 21, and the front and back surfaces are formed of solid layers, and a foam layer 27 is formed inside these solid layers.

  The back panel 19 is also formed in the same manner as the front panel 17. In addition, the 2nd type | mold used for shaping | molding of the back side panel 19 is formed with the recessed part corresponding to the panel side welding ribs 41a-41e, the reinforcement ribs 43 and 44, and the cross rib 46. FIG. The resin filled in the recess is cooled early by the mold temperature of the second mold, and even if the second mold is retracted to form the foam layer 39, the ribs 41a to 41e, 43, A foamed layer is not generated in 44 and 46, and a solid layer is formed.

  The reinforcing member 20 is formed by normal injection molding.

  And the front side panel 17, the back side panel 19, and the reinforcement member 20 comprised as mentioned above are vibration-welded. First, the front panel 17 is set on the upper vibration welding jig so that the back surface faces downward. On the other hand, the back side panel 19 is set on the lower vibration welding jig so that the panel side welding ribs 41a to 41e face upward. Thereafter, the reinforcing member 20 has a lower surface portion 20d surface in contact with the back surface of the panel main body 33 of the back panel 19 and the protruding end 43a of the reinforcing rib 43 of the back panel 19 is fitted and engaged with the engaging groove 49. 20 is mounted on the back panel 19 and assembled. Alternatively, the back panel 19 may be set on the lower vibration welding jig after the reinforcing member 20 is assembled to the back panel 19. In this state, the engagement between the engaging groove 49 of the reinforcing member 20 and the protruding end 43a of the reinforcing rib 43 of the back side panel 19 prevents the reinforcing member 20 from moving in the vibration direction X with respect to the back side panel 19. The Further, the peripheral wall portions 23 and 35 of the front side panel 17 and the back side panel 19 are opposed to each other, and the side surface 19a of the back side panel 19 is positioned so as to have a predetermined width inside the side surface 17a of the front side panel 17. Thus, the inner side portion of the front panel 17 on the back surface of the panel body 21 is covered with the back panel 19 from the back side. From this state, the upper vibration welding jig is pressed against the lower vibration welding jig from above, and the front surface of the panel side welding ribs 41a to 41e of the back panel 19 and the front surface of the first welding rib 47 of the reinforcing member 20 are front side. The upper vibration welding jig is reciprocally vibrated in the longitudinal direction of the floor board 5 (longitudinal direction of the panel-side welding ribs 41a to 41e), that is, the vibration direction X shown in FIG. . At this time, the reinforcing member 20 does not move in the vibration direction X because the engaging groove 42 is engaged with the protruding end 43 a of the reinforcing rib 43.

  As a result, the front end portion of the first welding rib 47 of the reinforcing member 20 melts the solid layer 25 by pressure contact vibration with the solid layer 25 on the back surface of the panel body 21 of the front panel 17 as shown in FIGS. The solid layer 25 breaks through the solid layer 25 and penetrates into the foam layer 27 therein, and the foam layer 27 is melted in the foam layer 27 so that the foam layer 27 around the tip of the first weld rib 47 is melted and solidified. 45 is covered and integrated with the foam layer 27 and the solid layer 25. Similarly, the front end portions of the panel side welding ribs 41a to 41e of the back side panel 19 also penetrate the solid layer 25 by the pressure contact vibration with the solid layer 25 on the back surface of the panel body 21 of the front side panel 17 and enter the foam layer 27 therein. Then, the foam layer 27 around the front end portions of the panel-side welding ribs 41a to 41e is covered with the solid portion 45 melted and solidified and integrated with the foam layer 27 and the solid layer 25.

  Therefore, according to the present embodiment, since the reinforcing member 20 and the front panel 17 are welded to each other by the first welding rib 47, rattling of the reinforcing member 20 is prevented. Furthermore, the front end portion of the first welding rib 47 penetrates into the foam layer 27 of the front panel 17 and is welded and integrated with the foam layer 27 as well as the back surface side solid layer 25 of the panel body 21 and is covered with the hard solid portion 45. Therefore, compared with the case where it welds only on the surface of the solid layer 25, a welding area becomes large and high welding strength is obtained. As a result, the coupling state between the reinforcing member 20 and the front panel 17 is strengthened, the rattling of the first welding rib 47 is prevented, and the rigidity of the entire resin molded product can be ensured.

  Further, the front end portions of the panel side welding ribs 41 a to 41 e of the back side panel 19 penetrate into the foam layer 27 as well as the back surface side solid layer 25 of the panel body 21 of the front side panel 17, similarly to the first welding rib 47. Since the foamed layer 27 is also welded and integrated and covered with a hard solid portion 45, the coupling state of the front side panel 17 and the back side panel 19 is more firm and surely stabilized, and the rigidity of the entire floor board 5 is further increased. .

  Moreover, since the surrounding wall parts 23 and 35 of the front side panel 17 and the back side panel 19 do not mutually press, they are not welded mutually, The welding operation of the panel side welding ribs 41a-41e and the 1st welding rib 47 is not inhibited, and the front side panel 17 The end of the skin 29 on the surface of the peripheral wall 23 is prevented from generating lint and burrs due to friction with the peripheral wall 35 of the back side panel 19 during vibration welding, and the appearance is not deteriorated.

  Moreover, since the inside of the panel main bodies 21 and 33 of the front side panel 17 and the back side panel 19 is comprised by the foam layers 27 and 39, a weight is reduced compared with the case where the panel main bodies 21 and 33 are comprised only by a solid layer. In addition, the resin material cost is reduced.

  Although the penetration dimensions of the panel-side welding ribs 41a to 41e and the first welding rib 47 of the reinforcing member 20 into the foamed layer 27 are the same, the penetration dimensions of these welding ribs 41a to 41e and 47 are not the same. , Each may have a different length.

(Embodiment 2)
FIG. 8 shows a floor board 5 according to Embodiment 2 of the present invention. In the second embodiment, the shape of the front panel 17 is the same as that of the first embodiment, but the shapes of the back panel 19 and the reinforcing member 20 are different from those of the first embodiment.

  A base layer 51 made of a solid that is thicker than the solid layer 37 formed on the front and back surfaces of the panel body 33 is disposed at a contact position of the lower surface portion 20d of the reinforcing member 20 in the panel body 33 of the back side panel 19. 33 is formed over the front and back surfaces so as to integrally connect the solid layers 37 on the front and back surfaces, and the foam layer 39 is not formed on the base layer 51. The thickness of the base layer 51 is set to approximately ½ of the thickness of the panel body 33, and the front side (the lower side in FIG. 8) of the base layer 51 is flush with the solid layer 37 on the front side of the panel body 33. The concave strip portion 53 is formed along the panel side welding ribs 41a to 41e on the back side of the base layer 51 (the upper side in FIG. 8, ie, the front panel 17 side). A plurality of engaging grooves 55 are formed on the bottom surface of the concave strip portion 53 in a direction orthogonal to the longitudinal direction so as to be separated from each other in the longitudinal direction. Further, on the vehicle body rear side of the panel side welding rib 41b and the vehicle body front side of the panel side welding rib 41c, instead of the reinforcing rib 43 corresponding to the first embodiment, the vehicle body front side of the panel side welding rib 41b, and the panel A rib having the same shape as the reinforcing rib 44 on the vehicle body rear side of the side welding rib 41c is formed, and the cross rib 46 is not formed.

  Further, as shown in FIG. 9, a plurality of convex portions 57 extending in a direction orthogonal to the longitudinal direction are spaced apart from each other in the longitudinal direction so as to correspond to the engaging groove 55 on the lower surface portion 20 d of the reinforcing member 20. Is formed. Further, the engaging grooves 49 of the first embodiment are not formed in the side surface portions 20b and 20c of the reinforcing member 20.

  The front side panel 17 and the back side panel 19 are vibration welded in a state where the convex portion 57 of the reinforcing member 20 is engaged with the engaging groove 55 of the back side panel 19 and the reinforcing member 20 is positioned on the back side panel 19. The floor board 5 is integrated. Since the other configuration is the same as that of the first embodiment, the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  Next, in addition to the first to third molds, a fourth mold corresponding to the concave strip portion 53 is used for molding the back side panel 19 of the second embodiment, and the second mold is retracted. When foaming and expanding the thermoplastic resin, the fourth mold is not retracted, and the distance between the first mold and the fourth mold is maintained at the mold closed state. Further, during vibration welding, the reinforcing member 20 is engaged with the back side panel 19 in the longitudinal direction (vibration direction X) due to the engagement between the engaging groove 55 of the back side panel 19 and the convex portion 57 of the reinforcing member 20. Is prevented from moving to.

  In the case where the inside of the contact portion of the lower surface portion 20d of the reinforcing member 20 in the back panel 19 is configured by a foam layer, the foam layer of the contact portion is crushed by the pressing force from the front panel 17, and the back panel 19 is recessed. As a result, the first welding rib 47 of the reinforcing member 20 may not be welded to the front panel 17 or the welding strength may be insufficient. On the other hand, according to the second embodiment, the bottom surface 20d contact portion of the reinforcing member 20 in the back side panel 19 is constituted by the base layer 51 made of a thick solid, so that the pressing force is applied from the front side panel 17. It is hard to dent even if received. Therefore, the first welding rib 47 of the reinforcing member 20 can be reliably welded to the front panel 17.

(Embodiment 3)
FIG. 10 shows a floor board 5 according to Embodiment 3 of the present invention. In the third embodiment, the shape of the front side panel 17 is the same as that in the first embodiment, but the shapes of the back side panel 19 and the reinforcing member 20 are different from those in the first embodiment.

  On the vehicle body rear side of the panel side welding rib 41b of the back side panel 19 and the vehicle body front side of the panel side welding rib 41c, the vehicle body front side of the panel side welding rib 41b is used instead of the reinforcing rib 43 corresponding to the first embodiment. And the rib of the same shape as the reinforcement rib 44 of the vehicle body rear side of the panel side welding rib 41c is formed, and the cross rib 46 is not formed.

  Also, on the lower surface portion 20d side of the reinforcing member 20, a long second welding rib 59 made of solid is continuously integrated along the reinforcing member 20 from one end to the other end in the longitudinal direction. Projected. Further, the engaging grooves 49 of the first embodiment are not formed in the side surface portions 20b and 20c of the reinforcing member 20.

  Then, the surface of the lower surface portion 20d of the reinforcing member 20 is separated from the back surface of the panel body 33 between the panel side welding ribs 41b and 41c in the back side panel 19, and the second welding rib 59 is welded to the back side panel 19. Thus, the front panel 17 and the back panel 19 are integrated by vibration welding with the recesses S1 and S2 facing each other to constitute the floor board 5.

  That is, in the floor board 5 assembled in this way, the tip end portion of the second welding rib 59 breaks through the panel layer 33 rear surface side solid layer 37 of the back panel 19 and enters the foamed layer 39, and the tip end portion of the second welding rib 59 The surrounding foam layer 39 is covered with a solid portion 45 melted and solidified and integrated with the foam layer 39 and the solid layer 37 on the back side of the panel body 33 by welding. Then, the surface of the lower surface portion 20 d of the reinforcing member 20 and the back surface of the panel body 33 of the back side panel 19 approach each other by the intrusion dimension of the second welding rib 59, and the second welding rib 59 between the reinforcing member 20 and the back side panel 19. , That is, the corresponding length between the surface of the lower surface portion 20d of the reinforcing member 20 and the back surface of the panel body 33 of the back panel 19 is shortened. Further, the intrusion dimension of the first welding rib 47 is shorter than the intrusion dimension of the panel side welding ribs 41b and 41c. Since the other configuration is the same as that of the first embodiment, the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  When manufacturing the floor board 5 according to the third embodiment, the back panel 19 and the reinforcing member 20 are vibration welded by the second welding rib 59, and then the back panel 19 and the front panel 17 to which the reinforcing member 20 is welded. Vibration welding. The vibration welding method between the back panel 19 and the reinforcing member 20 is the same as the vibration welding method between the panels 17 and 19 described in the first embodiment.

  Therefore, according to the third embodiment, since the reinforcing member 20 is also welded to the back panel 19 by the second welding rib 59, rattling of the reinforcing member 20 is more reliably prevented. Also in this case, the tip of the second welding rib 59 of the reinforcing member 20 penetrates into the foam layer 39 of the back panel 19 and is welded and integrated not only with the back layer solid layer 37 of the panel body 33 but also with the foam layer 39. Since it is covered with the hard solid portion 45, the connection state between the reinforcing member 20 and the back panel 19 becomes stronger and more reliable, and the rigidity of the entire floor board 5 is further increased.

  Further, since the penetration dimension of the first welding rib 47 is set shorter than the penetration dimension of the panel side welding ribs 41 b and 41 c, the front end surfaces of the panel side welding ribs 41 b and 41 c of the front side panel 17 are used during vibration welding. After contacting the back surface of the panel body 21, the front end surface of the first welding rib 47 of the reinforcing member 20 contacts the back surface of the panel body 21 of the front panel 17. Therefore, when the front end surface of the first welding rib 47 comes into contact with the panel body 21 of the front panel 17, the load from the front panel 17 is not distributed to the first welding rib 47 but is distributed to the panel side welding ribs 41 b and 41 c. Therefore, damage to the second welding rib 59 that supports the reinforcing member 20 from below is prevented.

  In the first to third embodiments, the peripheral wall portions 23 and 35 of the front panel 17 and the back panel 19 are close to each other, but are not welded to each other in a state where the panels 17 and 19 are completely welded. You may contact | abut.

  In the first and second embodiments, both the panel body 21 of the front panel 17 and the panel body 33 of the back panel 19 have the foam layers 27 and 39 inside, but the panel body 33 of the back panel 19. May be composed of only a solid layer.

  Moreover, in the said Embodiment 1-3, although the panel side welding rib 41a-41e was provided in the back side panel 19, you may provide the panel side welding rib 41a-41e in the front side panel 17. FIG. The structure for preventing the reinforcing member 20 from moving in the longitudinal direction is not limited to the structure of the first to third embodiments, and may be another structure. For example, you may make it project a stopper rib in the back side panel 19 corresponding to the longitudinal direction both ends of the reinforcement member 20. As shown in FIG.

  In the first to third embodiments, the skin 29 is provided only on the front panel 17. However, the skin 29 may be provided on the back panel 19 or may not be provided on either of the panels 17 and 19. Good.

  In the first to third embodiments, the case where the resin molded product is the floor board 5 is shown. However, other automotive resin molded products such as a package tray and a lid of a glove box, and further, a resin molded product other than an automobile. It can also be applied to.

  INDUSTRIAL APPLICABILITY The present invention is useful as a vibration welded structure of a resin molded product that is integrally welded by vibrating in a state where the first resin panel and the second resin panel are in pressure contact with each other.

It is a perspective view which shows the rear luggage compartment of the motor vehicle with which the floor board as a resin molded product which concerns on Embodiment 1 of this invention was attached. It is sectional drawing in the AA of FIG. It is a top view of a floor board. It is an expanded sectional view in the BB line of FIG. It is the C section enlarged view of FIG. It is a perspective view of a reinforcing member. It is a perspective view which expands and shows the back side panel back surface in the C section of FIG. FIG. 6 is a diagram corresponding to FIG. 5 of the second embodiment. FIG. 7 is a diagram corresponding to FIG. 6 of the second embodiment. FIG. 6 is a diagram corresponding to FIG. 5 of the third embodiment.

Explanation of symbols

5 Floorboard (resin molded product)
17 Front panel (first panel)
19 Back panel (second panel)
20 Reinforcing members 21, 33 Panel body 25, 37 Solid layers 27, 39 Foam layers 41a-41e Panel side welding rib 47 First welding rib 59 Second welding rib

Claims (3)

A vibration welded structure of a resin molded product obtained by welding and integrating the resin first panel and the resin second panel while being in pressure contact with each other,
The first panel has a panel body including a thin solid layer formed on the front and back surfaces, and a foam layer sandwiched between the solid layers and having a number of voids inside.
Between the first panel and the second panel, a long resin reinforcing member is sandwiched so as to extend in the vibration direction during vibration welding,
On the first panel side of the reinforcing member, an elongated first welding rib made of solid is integrally projected so as to follow the reinforcing member, and the tip end portion of the first welding rib is the above-mentioned first member during vibration welding. A vibration welded structure of a resin molded product, wherein the panel main body back side solid layer of one panel penetrates into the foamed layer and is integrally welded to the foamed layer and the solid layer. In the vibration welded structure of the resin molded product according to claim 1,
On the back surface of the second panel, a long panel-side welding rib made of solid is integrally projected toward the first panel side so as to extend in the vibration direction at the time of vibration welding,
The front end of the panel-side welding rib penetrates the solid layer on the back side of the panel body of the first panel during vibration welding and enters the foamed layer, and is welded and integrated with the foamed layer and the solid layer. Vibration welded structure of resin molded products. In the vibration welded structure of the resin molded product according to claim 1 or 2,
The second panel has a panel body including a thin solid layer formed on the front and back surfaces, and a foam layer sandwiched between the solid layers and having a large number of voids inside.
On the second panel side of the reinforcing member, an elongated second welding rib made of solid is integrally projected so as to follow the reinforcing member, and the tip end portion of the second welding rib is formed in the first position during vibration welding. A vibration welded structure of a resin molded product, characterized in that it breaks through a solid layer on the back side of the panel body of two panels and penetrates into the foamed layer, and is welded and integrated with the foamed layer and the solid layer.

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