JP4636604B2 - Molding method for multicolor molded products - Google Patents

Description

The present invention relates to a method for forming a multicolor molded article suitable for automobile interior parts such as a door trim, a rear parcel shelf, a floor trim, a luggage trim, a trunk trim, a rear side trim, and the like. The present invention relates to a method for forming a multicolor molded product that eliminates the protrusion protruding to the panel side, thereby eliminating the process of removing the protrusion and improving the productivity and improving the alignment accuracy with respect to the vehicle body panel.

  FIG. 17 is a front view showing an automotive door trim 1 having an upper and lower split structure. The automotive door trim 1 is composed of an upper and lower split body of a door trim upper 2 and a door trim lower 3, and the door trim upper 2 and the door trim lower are shown. The boundary groove portion 4 is set at the joint portion with 3. Next, the configuration of the molding die 5 for molding the door trim 1 will be described with reference to FIG. The molding die 5 includes a molding upper die 6 that can be moved up and down by a predetermined stroke, a molding lower die 7 that is fixed below the molding die 6, and injection machines 8a and 8b that are connected to the molding lower die 7 and supply molten resin. And a dividing bar 9 which is disposed in a boundary groove 4 between the door trim upper 2 and the door trim lower 3 and divides the cavity.

  And the process of shape | molding the door trim 1 which is a two-color molded product using this shaping die 5 is demonstrated. First, the upper mold 6 is lowered, and the upper and lower molds 6 and 7 are clamped. At this time, as shown in FIGS. 19 (a) and 19 (b), the dividing bar 9 is positioned upward to mold the cavity C1 and the door trim lower 3 for molding the door trim upper 2 by the extension operation of the cylinder 9a. And the cavity C2 is partitioned, and the molten resin M1 is injected and filled into the cavity C1 from the first injection machine 8a. In the cavity C1, the skin 2a of the door trim upper 2 is set in advance, and the door trim upper 2 made of a laminate of the skin 2a and the resin molded product 2b is molded.

  Thereafter, the cylinder 9a performs a contraction operation, and as shown in FIGS. 20A and 20B, after the dividing bar 9 is lowered, the molten resin M2 is injected and filled into the cavity C2 from the second injection machine 8b. Further, the molten resin M2 is filled in the space generated when the dividing bar 9 descends and is integrated with the door trim upper 2 so that the door trim lower 3 is formed into a required shape, and the door trim 1 is a two-color molded product. Is completed. A method for molding a two-color molded product such as the door trim 1 described above and a molding die are described in detail in Patent Document 1.

  FIG. 21 is a perspective view showing a terminal 4a of the boundary groove portion 4 of the door trim 1 formed by the above-described conventional molding method, and FIG. 22 is a cross-sectional view of the terminal 4a of the boundary groove portion 4. That is, at the terminal 4a in the boundary groove portion 4 between the door trim upper 2 and the door trim lower 3, a projection a corresponding to the downward stroke of the dividing bar 9 is projected toward the panel side, the appearance appearance is deteriorated, and between the body panel Cause interference problems. Therefore, the fact is that the protrusion a is cut along the cut line indicated by the arrow in FIG. 22 to improve the appearance and improve the alignment accuracy with respect to the vehicle body panel.

JP-A-10-278060

  As described above, conventionally, when a two-color molded product such as the automobile door trim 1 having an upper and lower divided structure is formed using the same molding die 5, the division is internally provided in the molding die 5. Since the bar 9 is required, a protrusion a having a dimension corresponding to the descending stroke of the dividing bar 9 is formed on the terminal 4a of the boundary groove portion 4, and a cutting process step for cutting the protrusion a is necessary, which increases the man-hours. There is a disadvantage of reducing productivity. Further, it has been pointed out that there is a problem that if the cutting process with high accuracy is not performed, the alignment accuracy between the vehicle body panel and the counterpart part is lowered.

The present invention has been made in view of such circumstances, the cavity in the molding die is partitioned by the dividing bars, multi-molded by injecting and filling a molten resin from a dedicated injection machine respectively each cavity This is a molding method for color molded products, which eliminates the process of removing protrusions at the end of the boundary groove along the joining line of multicolor molded products, eliminating the process of removing the projections, thereby increasing productivity. It is an object of the present invention to provide a method for forming a multicolor molded product that is enhanced and has improved accuracy of alignment with a body panel or a counterpart part.

In order to solve the above-mentioned problem, the present invention is configured such that, after the upper and lower molds are clamped, the dividing bar is raised in the cavity to partition the first cavity and the second cavity, and then the first After the molten resin is injected and filled into the cavity to mold the resin molded product on one side, the dividing bar is lowered, the molten resin is injected and filled into the second cavity, and the resin molded product on the other side Is formed with a resin molded product on one side through a boundary groove portion, and a groove portion is formed at the end of the dividing bar corresponding to the end of the boundary groove portion, and the other side When molding the plastic molded product, when the dividing bar descends, the vertical parting structure ensures the sealing performance between the molding upper die and the dividing bar, and the molding upper die is parted in this groove. By accommodating the protrusion, the terminal Characterized in that to be able to avoid the formation of protrusions extending in a direction.

  Here, the multi-color molded product is a plurality of different cavities set in at least two or more in a single molding die, and a plurality of different appearances are injected and filled in each cavity by a molten resin of different materials. It refers to a two-color molded product, a three-color molded product, etc. that are molded by joining and molding resin molded products. A skin can be laminated and integrated on the surface of the resin molded product on one side. For example, the multicolor molded product can be applied to automotive interior parts such as door trims, rear parcel shelves, floor trims, luggage trims, trunk trims, and rear side trims.

  As the material of the resin molded product, one kind of thermoplastic resin or two or more kinds of thermoplastic resins may be used. Preferably, polyethylene resin, polypropylene resin, polystyrene resin, polyethylene terephthalate resin, polyvinyl alcohol resin, vinyl chloride resin, polyamide resin, polyacetal resin, polycarbonate resin, ionomer resin, acrylonitrile / butadiene / Styrene (ABS) resin or the like can be used, and various fillers may be mixed in these thermoplastic resins. Examples of the filler that can be used include inorganic fibers such as glass fiber and carbon fiber, and inorganic particles such as talc, clay, silica, and calcium carbonate. Moreover, various additives, such as antioxidant, a ultraviolet absorber, a coloring agent, a flame retardant, and a low shrinkage agent, may be mix | blended.

  Further, a boundary groove portion is formed on the product surface along the joint portion of both resin molded products, and the end of this boundary groove portion is between the upper mold and the lower mold (including the divided bar). By adopting the vertical parting structure, a notch is formed in the bottom surface of the boundary groove.

And according to the molding method of the multicolor molded product according to the present invention, the boundary groove portion is provided between the resin molded products having different appearances, and the notch portion is formed at the end of the boundary groove portion. As described above, since the protrusion protruding to the panel side is not formed, the process of removing the protrusion can be eliminated, and a highly accurate alignment with the vehicle body panel and the counterpart part can be achieved.

  Here, the molding die used in the molding method according to the present invention is connected to a molding upper mold capable of moving up and down by a predetermined stroke, a molding lower mold positioned below the molding upper mold, and a molding lower mold. It is comprised from an injection machine and the division | segmentation mechanism part which is arrange | positioned at a shaping | molding lower mold | die and divides | segments a cavity. The dividing mechanism is supported so that the dividing bar can be moved up and down by a drive cylinder. At the time of molding the resin molded product on one side, the drive cylinder extends to divide the cavity with the dividing bar positioned above. Further, at the time of molding the resin molded product on the other side, the drive cylinder contracts and the dividing bar descends to form a space for communication between adjacent cavities. And the vertical parting structure is employ | adopted between the shaping | molding upper mold | type and the division | segmentation bar at the terminal of a boundary groove part.

  Therefore, according to the method for molding a multicolor molded product according to the present invention, at the end of the boundary groove portion at the time of molding the resin molded product on one side and the resin molded product on the other side, molding with the dividing bar Since a vertical parting structure is adopted between the upper mold and the upper mold, a notch is formed at the end of the boundary groove. As a result, the protrusion protruding toward the panel is not formed by the lowering of the dividing bar, and the protrusion cut removing process can be abolished.

As described above, the method for molding a multicolor molded product according to the present invention divides the cavity into a plurality of different cavities by the lifting and lowering operation of the dividing bar in the dividing mechanism portion arranged in the molding die, By injecting and filling molten resins of different colors into different cavities, a plurality of resin molded products can be joined and integrated with the boundary groove as a boundary. In particular, at the end of the boundary groove, a vertical parting structure is employed between the dividing bar and the upper mold, so that a notch is formed at the bottom of the groove at the end of the boundary groove. Therefore, unlike the conventional case, the projection protruding to the panel side is not formed at the end of the boundary groove portion, and it is possible to eliminate the process of removing the cut of the post-molding projection, which has been necessary in the past, and increase the productivity. In addition, there is an effect that it is possible to increase the alignment accuracy with respect to the vehicle body panel and the counterpart component without incurring accuracy failure due to cut variation or the like.

Hereinafter, a preferred embodiment of a method for forming a multicolor molded product according to the present invention will be described by exemplifying a method for forming an upper and lower split type automobile door trim . It should be noted that the gist of the present invention is specified only by the “Claims”, and the following embodiments are merely examples of the present invention.

  1 to 16 show an embodiment of the present invention. FIG. 1 is a front view of a door trim which is an embodiment of a multicolor molded product according to the present invention, and FIG. 2 is a sectional view showing the structure of the door trim. 3 is a perspective view showing a terminal of the boundary groove in the door trim, FIG. 4 is a side view showing a terminal of the boundary groove in the door trim, FIG. 5 is a plan view showing a terminal of the boundary groove in the door trim, FIG. FIG. 7 is an overall view of a molding die used for molding the door trim and a partial cross-sectional view of the boundary groove portion. FIGS. 8 and 9 are an overall view showing a configuration of a dividing bar arranged in the boundary groove portion of the molding die. FIGS. 10 and 11 are explanatory views showing the structure of the dividing bar, and FIGS. 12 to 15 are explanatory views showing the door trim upper forming step and the door trim lower forming step in the door trim manufacturing method, respectively. 16 Is an explanatory view showing a modified example of the molding die with horizontal parting structure.

  1 and 2, a two-tone type door trim 10 for an automobile is composed of an upper and lower divided body of a door trim upper 20 made of a laminated structure and a door trim lower 30 made of a single resin. The door trim upper 20 is composed of a laminated structure in which a skin 22 is adhered to the surface of a resin base material 21, and the door trim lower 30 is composed of a synthetic resin injection molded body. The material of the resin base material 21 and the door trim lower 30 in the door trim upper 20 may be made of one kind of thermoplastic resin or two or more kinds of thermoplastic resins. Preferably, polyethylene resin, polypropylene resin, polystyrene resin, polyethylene terephthalate resin, polyvinyl alcohol resin, vinyl chloride resin, polyamide resin, polyacetal resin, polycarbonate resin, ionomer resin, acrylonitrile / butadiene / Styrene (ABS) resin or the like can be used, and various fillers may be mixed in these thermoplastic resins. Examples of the filler that can be used include inorganic fibers such as glass fiber and carbon fiber, and inorganic particles such as talc, clay, silica, and calcium carbonate. Moreover, various additives, such as antioxidant, a ultraviolet absorber, a coloring agent, a flame retardant, and a low shrinkage agent, may be mix | blended.

  As functional parts to be mounted on the door trim 10, an inside handle unit 11, a power window switch unit 12, and the like are attached to the door trim upper 20. On the other hand, the door trim lower 30 is provided with a door pocket opening 13, and a pocket back cover (made of a resin molded body) 14 is attached to the rear side of the door trim lower 30, as shown in FIG. The speaker grill 15 is provided integrally with the door trim lower 30 or separately. Reference numeral 16 in the figure denotes a door inner panel (vehicle body panel) to which the door trim 10 is attached.

  By the way, the automotive door trim 10 according to the present invention has an excellent appearance design due to the contrast effect on the appearance of the door trim upper 20 and the door trim lower 30, and between the door trim upper 20 and the door trim lower 30, The boundary groove part 17 is formed as a parting line. Further, according to the molding method using a molding die, which will be described later, this automobile door trim 10 has a notch 18 formed at the end 17a of the boundary groove 17 as shown in FIGS. In addition, the conventional protrusion is not formed, the process of removing the protrusion protruding to the panel side, which has been required conventionally, can be eliminated, and the alignment accuracy with respect to the door inner panel (vehicle body panel) 16 can be managed well. There is an advantage.

  Next, the configuration of the molding die 40 used for molding the door trim 10 described above will be described with reference to FIGS. First, as shown in FIG. 6, the molding die 40 used for molding the door trim 10 is paired with a molding upper die 41 and a molding upper die 41 that can move up and down by a predetermined stroke. The fixed lower mold 42 and two injection machines 43a and 43b connected to the molded lower mold 42 are generally configured. More specifically, the molding upper die 41 has a cavity portion 411 that matches the product shape, and is driven up and down by a predetermined stroke by an elevating cylinder 412 connected to the upper surface of the molding upper die 41. In addition, guide bushes 413 serving as a guide mechanism are provided at the four corners of the molding upper die 41.

  On the other hand, the molding lower die 42 is provided with a core portion 421 corresponding to the cavity portion 411 of the molding upper die 41. Further, in order to supply molten resin to the mold surface of the core portion 421, manifolds 422a and 422b and gates 423a and 423b are provided in the molding lower mold 42. Resins of the manifolds 422a and 422b and gates 423a and 423b are provided. In the first cavity 424 for forming the resin base material 21 of the door trim upper 20 in which the molten resins M1 and M2 supplied from the injection machines 43a and 43b through the passages are formed on the upper surface of the core portion 421, and the door trim lower 30 is fed into a second cavity 425 for molding. In addition, guide posts 426 that serve as a guide mechanism protrude from the four corners of the molded lower mold 42. The guide posts 426 guide guide bushes 413 when the molded upper and lower molds 41 and 42 are clamped and opened. The press posture of the molding upper die 41 can be properly maintained by being guided in.

  Further, as shown in FIG. 7, in order to form the boundary groove portion 17 in the door trim 10, a protrusion 414 protrudes from the forming upper mold 41, and a recess 427 corresponds to the forming lower mold 42 correspondingly. The dividing mechanism portion 50 is accommodated and disposed in the recess 427. The dividing mechanism section 50 includes a dividing bar 51 and a drive cylinder 52 that drives the dividing bar 51 up and down so as to move up and down by a predetermined stroke. In addition, when the door trim lower 30 is formed, a recess 51a for forming the reinforcing rib 31 is formed.

  As shown in FIGS. 8 and 9, the dividing mechanism portion 50 provided in the molding lower die 42 is provided along the boundary groove portion 17 of the door trim 10, and the dividing bar 51 is driven by the drive cylinder 52. 9, the first cavity 424 and the second cavity 425 are partitioned or communicated by moving up and down by the stroke indicated by the symbol L between the upper position indicated by the solid line and the lower position indicated by the alternate long and short dash line in FIG. 9. . In the present embodiment, in particular, the mold structure around the terminal 51 b of the dividing bar 51 is devised in order to form the notch 18 in the terminal 17 a of the boundary groove 17. That is, as shown in FIGS. 10 and 11, the forming upper die 41 is formed with parting protrusions 414 a extending from the ridges 414, and the dividing bars 51 are formed so as to correspond thereto. The terminal 51b is formed with a stepped portion 53 that extends from the recessed portion 51a and has a single lower portion, and a groove portion 54 that airtightly accommodates the parting projection 414a is formed therebelow. The dimensional relationship between the parting projection 414a and the step portion 53 and the groove portion 54 of the terminal 51b of the dividing bar 51 is as follows: the depth a of the step portion 53, the depth b of the groove portion 54, and the vertical height c of the step portion 53. When the distance e from the product terminal to the end of the step 53 and the depth d from the product terminal to the groove 54 are defined, the notch 18 is formed with a dimension d with respect to the thickness e of the terminal flange of the product. become.

  Next, a molding method for molding the door trim 10 using the molding die 40 will be briefly described with reference to FIGS. First, in the molding process of the door trim upper 20, the skin 22 is set in the first cavity 424. At this time, the skin 22 is held on the mold surface of the molding upper die 41 by a set pin (not shown) or a vacuum suction action. The skin 22 may be set in the cavity 424 with a movable frame. After the skin 22 is set, the elevating cylinder 412 of the molding upper die 41 is operated, the molding upper die 41 is lowered by a predetermined stroke, the molding upper and lower dies 41 and 42 are clamped, and the first injection machine 43a. The molten resin M1 is injected and filled into the first cavity 424 through the manifold 422a and the gate 423a. The injection timing of the molten resin M1 may be set before the mold upper and lower molds 41 and 42 are clamped. Further, as this molten resin M1, Sumitomo Noblen BUE81E6 (polypropylene manufactured by Sumitomo Chemical Co., Ltd., melt index = 65 g / 10 min) is used. If desired, talc may be mixed in an appropriate proportion.

  As described above, the molten resin M1 is injected and filled into the first cavity 424, and the resin base material 21 with the skin 22 bonded thereto is molded, and the molding of the door trim upper 20 is completed. At this time, the boundary groove 17 , The drive cylinder 52 is in an extended state, and the division bar 51 is located at the uppermost position, and as shown in FIG. The molten resin M1 injected and filled into the second cavity 425 does not enter the second cavity 425 due to the sealing action of the dividing bar 51. At this time, as shown in FIG. 13, the terminal 51b of the dividing bar 51 is sealed by the molding upper die 41 and the vertical parting structure.

  Thereafter, when the molding of the door trim upper 20 is completed, the drive cylinder 52 in the dividing mechanism 50 is contracted, the dividing bar 51 is lowered by a predetermined stroke, and the door trim lower is passed from the second injector 43b through the manifold 422b and the gate 423b. The molten resin M2 is injected and filled into the second cavity 425 for molding, and the door trim lower 30 is molded into a required shape as shown in FIG. At the time of molding the door trim lower 30, the dividing bar 51 in the dividing mechanism portion 50 is lowered to the lower position. The terminal 51b of the dividing bar 51 has a boundary groove portion 17 as shown in FIG. In the terminal 17a, a parting projection 414a provided on the molding upper die 41 and the dividing bar 51 have a vertical parting structure, and in particular, in the groove portion 54 provided in the terminal 51b of the dividing bar 51 By accommodating the projection 414a, the notch 18 is formed at this portion.

  As described above, in the above-described embodiment, the step portion 53 and the groove portion 54 are formed in the terminal 51 b of the dividing bar 51, and the parting projection 414 a of the molding upper die 41 and the terminal 51 b of the dividing bar 51 are vertically connected. By parting, it is possible to form a slight notch 18 on the bottom surface of the groove 17 at the end 17a of the boundary groove 17, so that it is possible to avoid the formation of a conventional protrusion, and it is not necessary to remove the protrusion protruding to the panel side. It can be expected that the door inner panel (vehicle body panel) 16 or an adjacent mating part is accurately aligned. In the above-described embodiment, the vertical parting structure is adopted between the dividing bar 51 and the upper molding die 41. However, as shown in FIG. 16, the horizontal parting between the upper molding die 41 and the lower molding die 42 is performed. A parting plane P may be set so as to correspond to the alignment of the terminal 51b of the dividing bar 51.

  Further, in the above-described embodiment, the door trim 10 is shown as a two-color molded product. However, for example, a three-color molded product that divides the product into three parts such as a trim upper, a trim center, and a trim lower may be used. .

  The embodiment described above is a door trim 10 having a vertically divided structure including a door trim upper 20 and a door trim lower 30, and a structure composed of a laminated structure of a resin base material 21 and a skin 22 is applied as the door trim upper 20. However, it can also be applied to the door trim upper 20 made of a single resin molded product. Moreover, it can be applied to a three-color molded product in addition to a two-color molded product. Thus, if it is a multi-color molded product, it can be applied to all interior parts such as a rear parcel shelf, floor trim, luggage trim, trunk trim, rear side trim, and the like. Furthermore, it may be applied to at least one side of the terminal 17a of the boundary groove part 17, but it can be set to both terminals as desired.

It is a front view which shows the two-tone type vehicle door trim to which the multicolor molded article which concerns on this invention is applied. It is the II-II sectional view taken on the line in FIG. It is a perspective view which shows the terminal of the boundary groove part in the door trim for motor vehicles shown in FIG. It is a side view which shows the structure of the boundary groove part shown in FIG. It is A arrow directional view in FIG. It is a schematic diagram which shows the whole structure of one Example of the shaping | molding die used for the shaping | molding method of the multicolor molded product which concerns on this invention. It is explanatory drawing which shows the structure of the division mechanism part in the shaping die shown in FIG. It is explanatory drawing which shows the structure of the shaping die in the shaping die shown in FIG. 6, and a division | segmentation mechanism part. It is sectional drawing which shows the structure of the terminal of the division | segmentation bar in the division | segmentation mechanism part shown in FIG. It is explanatory drawing which shows the structure of the terminal of the division | segmentation bar in the division | segmentation mechanism part shown in FIG. It is a schematic diagram of the boundary groove part formed by the division | segmentation bar shown in FIG. It is explanatory drawing which shows the molding process of the door trim upper at the time of applying the shaping | molding method of the multicolor molded product which concerns on this invention to the shaping | molding method of a door trim. It is explanatory drawing which shows the positional relationship of the division | segmentation bar at the time of shaping | molding of the door trim upper shown in FIG. It is explanatory drawing which shows the molding process of the door trim lower at the time of applying the shaping | molding method of the multicolor molded product which concerns on this invention to the shaping | molding method of a door trim. It is explanatory drawing which shows the positional relationship of the division | segmentation bar at the time of shaping | molding of the door trim lower shown in FIG. It is sectional drawing which shows the modification of the shaping die which shape | molds the multicolor molded product which concerns on this invention. It is a front view which shows the conventional two-tone type door trim. It is explanatory drawing which shows the whole structure of the shaping die used for shaping | molding of the conventional two-tone type door trim. It is explanatory drawing which shows the formation process of the door trim upper in the manufacturing method of the conventional door trim shown in FIG. It is explanatory drawing which shows the formation process of the door trim lower in the manufacturing method of the conventional door trim shown in FIG. It is a perspective view which shows the terminal shape of the boundary groove part in the conventional door trim. It is sectional drawing which shows the terminal process process of the boundary groove part in the conventional door trim.

Explanation of symbols

10 Automotive door trim (two-tone type)
17 Boundary groove 17a End 18 Notch 20 Door trim upper 21 Resin base material 22 Skin 30 Door trim lower (single resin)
40 Molding mold 41 Molding upper mold 414 Projection 414a Parting projection 42 Molding lower mold 424 First cavity (for door trim upper molding)
425 Second cavity (for door trim lower molding)
43a, 43b Injection machine 50 Dividing mechanism part 51 Dividing bar 51a Recessed part 51b Terminal 52 Drive cylinder 53 Step part 54 Groove part M1, M2 Molten resin

Claims (1)

After clamping the molding upper and lower molds (41, 42), the dividing bar (51) is raised in the cavity (C) to partition the first cavity (424) and the second cavity (425), Next, the molten resin (M1) is injected and filled into the first cavity (424), and after molding the resin molded product (20) on one side, the dividing bar (51) is lowered, A melt resin (M2) is injected and filled into the cavity (425), and the resin molded product (30) on the other side is integrated with the resin molded product (20) on the one side through the boundary groove (17). A molding method for a color molded product (10), comprising:
  A groove portion (54) is formed at the end (51b) of the dividing bar (51) corresponding to the end (17a) of the boundary groove portion (17), and it is divided at the time of molding the resin molded product (30) on the other side. When the bar (51) descends, the sealing performance is ensured by the vertical parting structure between the molding upper die (41) and the dividing bar (51), and the molding upper die (41) is placed in the groove (54). The parting projection (414a) is accommodated so that the formation of the projection extending downward in the terminal (17a) can be avoided.

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