JP2019166652A - Manufacturing method of formed structure - Google Patents

Abstract

To improve a dimensional accuracy of an end portion and to ensure uniformity of a rigidity of the end portion.SOLUTION: A manufacturing method of a formed structure 20 that comprises a base material 31 and a formed body 50 formed on a peripheral end portion 23 of the base material 31 includes a press-forming step and a main forming step for forming the formed body 50 on the peripheral end portion 23 by injecting a thermoplastic resin constituting the formed body 50 while press-forming the base material 31 with forming dies 61, in which the forming dies 61 is provided at a position facing the peripheral end portion 23 with a sliding die 80 slidable toward the peripheral end portion 23. The main forming step includes a forming space creating step for creating a forming space S by advancing the sliding die 80 in a direction of pressing of the peripheral end portion 23 of the base material 31 for pressing the peripheral end portion 23 and subsequently retracting the sliding die 80, at the time following press-forming of the base material 31 and prior to injection of a thermoplastic resin, and an injection step for injecting the thermoplastic resin into the forming space S.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a method for manufacturing a molded structure.

  Conventionally, a method described in Patent Document 1 is known as a method for manufacturing a molded structure. The method for producing a molded structure described in Patent Document 1 is a method for producing a molded structure in which a molded body is injection-molded on a substrate formed by entanglement of fibers with each other, and the fibers are combined with a thermoplastic resin. Heating and primary forming to form a pre-board, and pre-board is heated again to form a base material, and a low-density part with low fiber density is formed on a part of the base material A secondary molding step, and a simultaneous molding step of simultaneously molding a molded body by injecting a molten resin into the low density portion in the state of secondary molding.

JP 2009-113244 A

  By the way, in the manufacturing method of a molded structure as disclosed in Patent Document 1, in order to improve rigidity, by injecting a thermoplastic resin to the end of the base material, the base material is crushed by the injection pressure, A two-layer structure of a base material and a thermoplastic resin may be formed. In this case, it is difficult to make the injection pressure of the thermoplastic resin uniform at the end portion of the base material, and depending on the part, there may be variations in the plate thickness of the end portion. Then, it is conceivable that the thermoplastic resin is cooled, and deformation that undulates at the end portion occurs.

  The present invention has been completed based on the above-described circumstances, and can produce a molded structure that can improve the dimensional accuracy of the end and can ensure the rigidity of the end uniformly. It aims to provide a method.

  The present invention is a method for producing a molded structure comprising: a base material composed of at least fibers and a thermoplastic resin; and a molded body composed of at least a thermoplastic resin and molded at an end of the base material. A press molding step of press-molding the base material with a molding die, and a thermoplastic resin constituting the molded body is injected while the base material is press-molded with the molding die; A main molding step of molding the molded body, and the molding die includes a slide mold that is slidable toward the end portion at a position facing the end portion, and the main molding step includes: After press-molding the base material and before injecting the thermoplastic resin, the slide mold is advanced in a direction to press the end part of the base material and then the end part is pressed, and then the slide Retreated mold A molding space creating step of creating a molding space in Rukoto, the molding space, characterized in that includes an injection step of injecting a thermoplastic resin.

  According to such a manufacturing method of a molded structure, since the molding space is created by pressing the end portion with a slide mold in the molding space creation step, compared with the case where the end portion is pressurized with the injection pressure of the thermoplastic resin. Thus, the end can be pressurized with a uniform force. Then, a predetermined molding space such as a uniform thickness can be created. In addition, since the thermoplastic resin is injected into the molding space in the injection process, even if the thermoplastic resin is cooled, the end portion is unlikely to be deformed.

  In the above configuration, the main forming step may form the molded body at a peripheral end portion located at a peripheral end of the base material. According to such a method for producing a molded structure, a molded structure having a uniform peripheral end thickness can be produced. As a result, the rigidity of the peripheral end portion of the molded structure can be made uniform, and the deterioration of the design property due to the occurrence of undulating deformation at the peripheral end portion can be prevented. Therefore, for example, a suitable molded structure can be provided for a member having a peripheral end portion that requires strength and design, such as a door trim upper.

  In the above configuration, the slide mold has a concavo-convex concavo-convex portion on a front end surface thereof, and the forming space creating step presses the end portion so that the concavo-convex portion becomes a surface pressing the end portion. can do. In the molding space creation step, the end portion is cooled by contacting the slide mold. Then, in an injection process, a temperature difference arises between an edge part and a thermoplastic resin, and there exists a possibility that the joining strength may fall. However, according to such a method of manufacturing a molded structure, the slide mold has a concavo-convex concavo-convex portion on the tip surface thereof, and the concavo-convex portion is a surface that presses the end portion in the molding space creation step. Since the end portion is pressed, an uneven portion can be formed at the end portion. In the subsequent injection step, when the thermoplastic resin is injected into the molding space, the interface between the end portion and the thermoplastic resin becomes uneven, so that the joint strength between the two can be improved due to the anchor effect.

  The said structure WHEREIN: The said slide type | mold is provided with the front-end | tip enlarged diameter part which becomes large as it goes to a front-end | tip, and the said formation space creation process can press the said edge part by the said front end enlarged part. According to such a method for manufacturing a molded structure, in the molding space creation step, only the tip of the tip diameter-enlarged portion can come into contact with the end portion and a portion other than the slide die in the molding die. Then, even if the thermoplastic resin is injected into the molding space in the injection process, the thermoplastic resin leaks from the boundary between the slide mold and the portion other than the slide mold in the mold, and enters the inside of the mold. Can be deterred.

  According to the present invention, it is possible to improve the dimensional accuracy of the end portion, and to ensure the rigidity of the end portion uniformly.

The front view which looked at the door trim which concerns on Embodiment 1 from the vehicle interior side Sectional view of door panel (cross-sectional view taken along line AA in FIG. 1) Sectional view showing the molding device in the open state in the press molding process Sectional view showing the molding device in the closed state in the press molding process Sectional drawing which shows the state which advanced the slide type | mold in the molding space creation process Sectional drawing which shows the state which retracted the slide type | mold in the molding space creation process Enlarged view of the molding space (corresponding to Fig. 6) Sectional view showing the molding device in the injection process Sectional view showing the door trim after the main molding process The enlarged view which looked at the hole for door inside handles which concerns on Embodiment 2 from the vehicle compartment outer side Sectional drawing which shows the state which advanced the slide type | mold in the shaping | molding space creation process (corresponding to the BB line cross section in FIG. 10) Sectional view showing the molding device in the injection process

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS. In addition, let the right side in FIG. 2 be the vehicle interior outside, and let the left side be the vehicle interior side. As shown in FIGS. 1 and 2, the vehicle door 10 includes a door panel 11 disposed outside the vehicle compartment, and a door trim (molded structure) 20 disposed on the vehicle interior side and attached to the door panel 11. . The door panel 11 includes an outer panel 12 disposed outside the passenger compartment, and an inner panel 13 disposed between the door trim 20 and the outer panel 12. The door trim 20 is provided with a door inside handle hole 25 for attaching a door inside handle, an armrest 26, a door pocket 27, and the like.

  As shown in FIG. 2, the door trim 20 has a shape that is bent outward from the passenger compartment as it goes upward. Moreover, the door trim 20 is comprised with the base material 31 comprised with a fiber and a thermoplastic resin, and the peripheral edge part (upper edge part in the base material 31) comprised by the thermoplastic resin and located in the peripheral end of the base material 31. 23, and a molded body 50 molded to 23. The interface 35 in the longitudinal direction of the sectional view where the peripheral end portion 23 of the base material 31 and the molded body 50 are joined forms an uneven shape.

  Thus, the rigidity of the end portion of the door trim 20 is increased by forming a two-layer structure of the base material 31 and the molded body 50 at the end portion of the base material 31 such as the peripheral end portion 23. In addition, as the fiber, a fiber selected from wood fibers obtained by weaving wood, bast plant fibers such as kenaf, inorganic fibers such as glass fibers and carbon fibers, synthetic resin fibers, and the like can be used. . In addition, polypropylene can be used as the thermoplastic resin.

  Next, the molding apparatus 60 for manufacturing the door trim 20 will be described with reference to FIGS. The molding device 60 includes a pair of molding dies 61 for molding the base material 31 by pressing the pre-board P from above and below, and an injection device (not shown) for injecting a thermoplastic resin. The pair of molding dies 61 is arranged on the upper side, and is arranged on the lower side so as to face the upper die 70 and the upper die 70 that presses the surface of the pre-board P that becomes the surface (surface on the vehicle interior side) of the base material 31. And a lower mold 71 that presses a surface of the pre-board P that is to be a back surface (a surface outside the passenger compartment) of the base material 31.

  The upper mold 70 is a movable mold that can move in the vertical direction with respect to the lower mold 71 by a driving device (not shown) (for example, an electric motor, an air cylinder, a hydraulic cylinder, or the like). FIG. 3 shows a state in which the upper mold 70 has moved in a direction away from the lower mold 71, that is, a state in which the forming mold 61 is opened (open state). 4 to 8 show a state in which the upper die 70 has moved in a direction approaching the lower die 71, that is, a state in which the molding die 61 is closed (closed state). In the open state shown in FIG. 3, after the plate-like preboard P is disposed between the upper mold 70 and the lower mold 71, when the molding die 61 is closed, as shown in the closed state shown in FIG. The base material 31 is molded by being pressed by the mold 70 and the lower mold 71. The preboard P is a plate-like body obtained by pressing a laminate obtained after matting a material in which fibers and a thermoplastic resin are mixed into a plate shape.

  As shown in FIGS. 4 to 8 in the closed state, the lower mold 71 is slidable toward the back surface 23A by a driving device (not shown) at a position facing the back surface 23A of the peripheral end 23 of the base material 31. A slide mold 80 and a portion 72 other than the slide mold 80 are included.

  Further, as shown in FIG. 7, the slide mold 80 includes a tip diameter-enlarging portion 81 having a trapezoidal cross-sectional shape and a diameter d that increases toward the right tip 82. The tip diameter-enlarging portion 81 has a concavo-convex portion 83 having a concavo-convex shape on a surface (tip surface) 81 </ b> A facing the back surface 23 </ b> A of the peripheral end portion 23, which is a surface at the right tip 82. When the slide mold 80 is slid, only the tip 82 can be in contact with the side wall surface 23B on the back side of the peripheral end portion 23 and the wall surface 72A inside the portion 72 other than the slide mold 80. ing.

  Next, a method for manufacturing the door trim 20 using the molding apparatus 60 will be described with reference to FIGS. The manufacturing method of the door trim 20 according to the present embodiment is roughly classified into a press molding process in which the base material 31 is press-molded by the molding die 61 and the molded body 50 while the base material 31 is press-molded by the molding die 61. A main molding step of injecting a thermoplastic resin and molding the molded body 50 on the peripheral end portion (end portion) 23.

<Press molding process>
The plate-like preboard P is heated to such an extent that the thermoplastic resin is melted and softened again, and is arranged between the upper mold 70 and the lower mold 71 of the mold 61 in the open state shown in FIG. Thereafter, the upper die 70 is brought close to the lower die 71 at a predetermined pressure as in the closed state shown in FIG. Thereby, the pre-board P is press-molded by the molding die 61, and the base material 31 having a shape bent downward (outside the vehicle compartment) toward the right is molded.

<Main molding process>
After the base material 31 is press-molded from the preboard P, as shown in FIG. 5, the slide die 80 is pressed in the direction in which the back surface 23A of the peripheral end portion 23 of the base material 31 is pressed (the direction in which the end portion of the base material is pressed). Move forward. Then, the concavo-convex portion 83 of the tip enlarged diameter portion 81 becomes a surface (tip surface) 81A that presses the peripheral end portion 23 and presses the peripheral end portion 23.

  As the slide mold 80 is further advanced, the peripheral end portion 23 of the base material 31 in which the thermoplastic resin is melted and softened is crushed so as to follow the uneven shape of the uneven portion 83 in the tip enlarged diameter portion 81. Then, the back surface 23A of the peripheral end portion 23 comes into close contact with the front end surface 81A.

After the peripheral end 23 is pressed to a predetermined thickness by the advancement of the slide mold 80, as shown in FIGS. 6 and 7, the slide mold 80 is moved backward to the left so as to be separated from the peripheral end 23. A longitudinally shaped molding space S is created on the back side of the peripheral end 23 (molding space creation step).
At this time, the slide die 80 is retracted to a position before pressing the peripheral end portion 23 (a position corresponding to FIG. 4), and the position is maintained. The right side of the molding space S is surrounded by the back surface 23 </ b> A of the peripheral end portion 23, and the left side thereof is surrounded by the front end surface 81 </ b> A of the front end enlarged diameter portion 81. Accordingly, the thickness of the molding space S in the short side direction in cross section is uniform in the vertical direction.

  A thermoplastic resin (molten resin) 51 heated and melted is injected into the molding space S from an injection device (not shown) provided with injection holes communicating with the molding space S (injection process). Then, as shown in FIG. 8, the molten resin 51 fills the molding space S. That is, by continuing to inject the molten resin 51 into the molding space S while maintaining the position of the slide mold 80, the molten resin 51 fills the molding space S so as to fill the concave and convex shapes of the two surfaces 23A and 81A. To go.

  After the molding space S is filled with the molten resin 51, the molten resin 51 is cooled and solidified. Then, the mold 61 is opened and the molded structure is removed from the mold. Then, as shown in FIG. 9, the manufacture of the door trim 20 including the base material 31 and the molded body 50 (cooled molten resin 51) molded on the peripheral end portion 23 of the base material 31 is completed.

  Then, the effect of this embodiment is demonstrated. In the present embodiment, a molded structure 20 including a base material 31 composed of at least fibers and a thermoplastic resin, and a molded body 50 composed of at least a thermoplastic resin and molded at the end of the base material 31. A press molding step of press-molding the base material 31 with the molding die 61, and a thermoplastic resin (molten resin) 51 constituting the molded body 50 while press-molding the base material 31 with the molding die 61. A molding step in which the molded body 50 is molded at the end, and the molding die 61 is provided with a slide die 80 slidable toward the end at a position facing the end. In this molding step, after the base material 31 is press-molded and before the thermoplastic resin 51 is injected, the end portion is moved by advancing the slide mold 80 in the direction in which the end portion of the base material 31 is pressed. After pressing A molding space creating step of creating a molding space S to slide 80 by retracting, the molding space S, characterized in that includes an injection step of injecting the thermoplastic resin 51.

  According to such a manufacturing method of the molded structure 20, since the molding space S is created by pressing the end portion with the slide mold 80 in the molding space creating step, the end portion is added by the injection pressure of the thermoplastic resin 51. As compared with the case of pressing, the end portion can be pressed with a uniform force. And the predetermined shaping | molding space S, such as uniform thickness, can be created. In addition, since the thermoplastic resin 51 is injected into the molding space S in the injection process, even if the thermoplastic resin 51 is cooled, the end portion is unlikely to be deformed.

  In the present embodiment, in the main forming step, the formed body 50 can be formed on the peripheral end portion 23 located at the peripheral end of the base material 31. According to such a manufacturing method of the molded structure 20, it is possible to manufacture the molded structure 20 in which the thickness of the peripheral end portion 23 is uniform. As a result, the rigidity of the peripheral end portion 23 in the molded structure 20 can be made uniform, and design deterioration due to undulating deformation occurring in the peripheral end portion 23 can be prevented. Therefore, for example, a suitable molded structure 20 can be provided for a member having a peripheral end portion 23 that requires strength and design, such as a door trim upper.

  In the present embodiment, the slide mold 80 has a concavo-convex concavo-convex portion 83 on its front end surface 81A, and the forming space creation step is performed so that the concavo-convex portion 83 becomes a surface that presses the peripheral end portion 23. The part 23 can be pressed. In the molding space creation step, the peripheral end 23 is cooled by contacting the slide mold 80. Then, in the injection process, a temperature difference is generated between the peripheral end portion 23 and the thermoplastic resin 51, and the bonding strength may be reduced. However, according to such a manufacturing method of the molded structure 20, the slide die 80 has the concave and convex portions 83 on the tip surface 81 </ b> A, and the concave and convex portions 83 form the peripheral end portion 23 in the molding space creation step. Since the peripheral end portion 23 is pressed so as to be a pressing surface, an uneven portion can be formed on the peripheral end portion 23. In the subsequent injection process, when the thermoplastic resin 51 is injected into the molding space S, the interface 35 between the peripheral end portion 23 and the thermoplastic resin 51 becomes uneven, thereby improving the joint strength between the two due to the anchor effect. Can be made.

  In the present embodiment, the slide mold 80 includes a tip enlarged portion 81 whose diameter d increases toward the tip 82, and the forming space creation step can press the peripheral end portion 23 by the tip enlarged portion 81. it can. According to such a manufacturing method of the molded structure 20, in the molding space creation step, only the tip 82 of the tip enlarged diameter portion 81 is the side wall surface 23 </ b> B on the back side of the peripheral end portion 23 and the slide die 80 in the molding die 61. It becomes possible to make contact with the inner wall surface 72 </ b> A of the portion 72. Then, even if the thermoplastic resin 51 is injected into the molding space S in the injection step, the thermoplastic resin 51 leaks from the boundary between the slide die 80 and the portion 72 other than the slide die 80 in the molding die 61. Intrusion into the inside of 61 can be suppressed.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIGS. In this embodiment, the manufacturing method of the door trim (molding structure) 220 in which the molded body is molded and the slide mold is different from the first embodiment is exemplified. In addition, in this embodiment, the description which overlaps the said embodiment and a structure, a manufacturing method, an effect | action, and an effect is abbreviate | omitted. Further, the front side of the page in FIG. 10 is defined as the vehicle interior side, the back side of the page is defined as the vehicle interior side, the left side in FIGS. 11 and 12 is defined as the vehicle interior side, and the right side is defined as the vehicle interior side.

  FIG. 10 is an enlarged view of the vicinity of the door inside handle hole 225 provided in the door trim 220 as viewed from the back side of the door trim 220 (outside the passenger compartment). The door trim 220 is composed of a base material 231 composed of fibers and thermoplastic resin, and an end of the base material 231 near the door inside handle hole 225 that penetrates the vehicle interior side and the vehicle interior outside. A molded body 250 molded into the portion 224. The end 224 can be said to be a portion surrounding the door inside handle hole 225 in the base material 231.

  Next, the molding apparatus 260 for manufacturing the door trim 220 will be described with reference to FIGS. 11 and 12. The molding apparatus 260 includes a pair of molds 261 that mold the base material 231 by pressing a preboard from the left and right directions, and an injection apparatus (not shown) that injects a thermoplastic resin. The pair of molds 261 is disposed on the right side, and is disposed on the left side so as to face the upper mold 270 and the upper mold 270 that molds the surface of the base member 231 (the surface on the vehicle interior side). And a lower mold 271 that molds the back surface (surface outside the passenger compartment).

  The lower mold 271 has a columnar hole forming portion 273 capable of forming a door inside handle hole 225 in the preboard by closing the forming mold 261 on which the preboard is arranged. Further, the lower mold 271 is a position facing the back surface of the end portion 224 of the base material 231 and is slidable around the hole forming portion 273 toward the back surface of the end portion 224 by a driving device (not shown). A mold 280 is included. Further, the lower die 271 has a main body portion 272 that is a portion other than the hole forming portion 273 and the slide die 280. That is, the lower mold 271 includes a main body portion 272, a slide mold 280, and a hole forming portion 273.

  Next, a method for manufacturing the door trim 220 by the molding apparatus 260 will be described with reference to FIGS. In the press molding process, the plate-shaped preboard is heated to such an extent that the thermoplastic resin is melted and softened again, and is placed between the upper mold 270 and the lower mold 271 in the open state (not shown). Thereafter, in the closed state, the upper mold 270 and the lower mold 271 are closed and held for a predetermined time. Thereby, the preboard is press-molded by the molding die 261, and the base material 231 having the door inside handle hole 225 penetrating the vehicle interior side and the vehicle interior outside is molded.

  As shown in FIG. 11, the end 224 is pressed to a predetermined thickness by the advancement of the slide mold 280. Thereafter, when the slide mold 280 is retracted to the left so as to be separated from the end portion 224, a molding space (not shown) having a longitudinal cross-sectional view is on the back side of the end portion 224 and around the hole forming portion 273. (Molding space creation process).

  A thermoplastic resin (molten resin) 251 that has been heated and melted is injected into this molding space from an injection device (not shown) (injection process). As shown in FIG. 12, after the molten resin 251 is filled in the molding space, the molten resin 251 is cooled and solidified. Then, the mold 261 is opened, and the molded structure is removed from the mold. Then, as shown in FIG. 10, a door trim 220 including a base material 231 and a molded body 250 (cooled molten resin 251) formed on the base material 231 at an end 224 near the door inside handle hole 225. Is completed.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.

  (1) In addition to the above embodiment, the position at which the slide mold is retracted in the molding space creation step can be changed as appropriate. In the above embodiment, the slide mold moves forward and presses the end portion, and then retracts to the vicinity of the position before pressing the end portion. However, the present invention is not limited to this. For example, the slide mold may be moved backward slightly after being advanced and pressing the end. If the small gap obtained in this way is used as a molding space, in the injection process, molten resin is injected into the molding space, and the molded body is formed by retreating the slide mold to a predetermined position by the injection pressure. Can do.

  (2) Other than the above embodiment, the molded structure can be changed as appropriate. In the said embodiment, although the door trim was illustrated as a shaping | molding structure, it is not restricted to this. For example, the molded structure may be a member such as a seat backboard, a roof trim, or a pillar garnish.

  (3) In the above-described embodiment, as the end portion of the base material, the upper end portion (circumferential end portion) of the base material and the end portion near the door inside handle hole are exemplified, but the present invention is not limited thereto. For example, the end portions may be left and right end portions or a lower end portion of the base material.

  (4) The manufacturing method of the molded structure exemplified in the above embodiments is not limited to that provided to the vehicle, and may be provided in various vehicles. For example, the method of manufacturing a molded structure can be applied to vehicles such as trains and play vehicles as ground vehicles, airplanes and helicopters as flying vehicles, and ships and submersibles as marine and underwater vehicles. it can.

  DESCRIPTION OF SYMBOLS 10 ... Door, 20, 220 ... Door trim (molded structure), 23 ... Peripheral edge, 25, 225 ... Door inside handle hole, 31, 231 ... Base material, 35 ... Interface, 50, 250 ... Molded body, 60 , 260 ... Molding device, 61, 261 ... Mold, 70, 270 ... Upper mold, 71, 271 ... Lower mold, 80, 280 ... Slide mold, 81 ... Tip diameter expansion part, 81A ... Tip surface, 82 ... Tip, 83: Uneven portion, 224: End near the door inside handle hole, 272 ... Main body portion, 273 ... Hole forming portion, P ... Preboard, S ... Molding space, d ... Diameter

Claims (4)

A substrate composed of at least a fiber and a thermoplastic resin;
A method for producing a molded structure comprising at least a thermoplastic resin and a molded body molded at an end of the base material,
A press-molding step of press-molding the substrate with a mold;
A main molding step of injecting a thermoplastic resin constituting the molded body and molding the molded body at the end while press-molding the base material with the molding die,
The mold is provided with a slide mold that is slidable toward the end at a position facing the end.
The main molding step
After press-molding the base material and before injecting the thermoplastic resin, the slide mold is advanced in a direction to press the end part of the base material and then the end part is pressed, and then the slide A molding space creation process for creating a molding space by retracting the mold,
An injection process for injecting a thermoplastic resin into the molding space.   2. The method for manufacturing a molded structure according to claim 1, wherein in the main molding step, the molded body is molded at a peripheral end portion located at a peripheral end of the base material. The slide mold has a concavo-convex portion on the tip surface,
3. The method for manufacturing a molded structure according to claim 1, wherein the forming space creating step presses the end portion so that the uneven portion becomes a surface pressing the end portion. . The slide mold includes a tip enlarged portion whose diameter increases toward the tip,
The method for manufacturing a molded structure according to any one of claims 1 to 3, wherein in the molding space creating step, the end portion is pressed by the tip enlarged diameter portion.

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