JP2007130914A - Multicolor molded article and its molding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent resin leakage in a parting part and increase the joint strength of the parting part, in a multicolor molded article which is constituted by making a splitting bar ascend/descend in a cavity so as to split a cavity, and inject and infill molten resins of different colors into the respective split cavities, and a molding method for the multicolor molded article. <P>SOLUTION: A top surface 52 of the splitting bar 50 for dividing the cavity C defined by a mold 40 is set in a step-part surface shape which is equipped with a plurality of step parts 53a, 53b and 53c. Thus, the molten resin M1 injected and infilled into the first cavity C1 collides with the step parts 53a, 53b and 53c as it advances toward a terminal end, and the flow rate of the resin is reduced. This prevents the resin leakage, and enables the joint strength to be increased because resin molded articles 20 and 30 are joined along the step-part surface shape. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a multicolor molded article suitable for automobile interior parts such as an automobile door trim, a luggage trim, a trunk trim, and the like, and a molding method thereof. In particular, the appearance performance of a product surface near a parting line can be improved. The present invention relates to a color molded product and a molding method thereof.

  FIG. 9 is a front view showing an automotive door trim that is a representative part of automotive interior parts. The automotive door trim 1 includes a door trim upper 2 and a door trim lower 3 in order to enhance the appearance design. It consists of two-color molded products with different colors.

  The configuration of the molding die 4 for molding the door trim 1 will be described with reference to FIGS. 10 and 11. The molding die 4 has a movable die 5 and a fixed die 6 clamped to each other. A split bar 7 is provided on the stationary mold 6 at a parting section that divides the door trim upper 2 and the door trim lower 3. The dividing bar 7 is moved up and down by a predetermined stroke by the drive cylinder 7a. When the door trim upper 2 is molded, the split bar 7 faces the cavity 8 by driving the drive cylinder 7a. , The molten resin M1 on the side of the door trim upper 2 is prevented from entering the door trim lower molding cavity 8b, and when the door trim lower 3 is molded, the dividing bar 7 moves backward, and the door trim upper 2 and the door trim are separated. Integral molding with the lower 3 is performed.

  That is, when the door trim upper 2 is molded, as shown in FIG. 11A, the dividing bar 7 is lifted into the cavity 8 defined by the movable side mold 5 and the fixed side mold 6. 7 is abutted against the mold surface of the movable mold 5, and is divided into a door trim upper molding cavity 8a and a door trim lower molding cavity 8b. Thereafter, molten resin M1 is injected and filled into the door trim upper molding cavity 8a, and the door trim upper 2 is first molded into a required shape.

  When the molding of the door trim upper 2 is completed, as shown in FIG. 11 (b), the dividing bar 7 is lowered and retracted from the cavity 8 by the contraction operation of the drive cylinder 7a, and the door trim lower molding cavity 8b. The molten resin M2 is injected and filled therein, and the door trim lower 3 is molded integrally with the door trim upper 2 to complete the molding of the door trim 1 shown in FIG. A conventional example of forming a two-color molded product using a dividing bar in the same mold is shown in detail in Patent Document 1.

JP-A-8-267479

Thus, conventionally, in order to form a two-color molded product (door trim 1) using the same molding die 4, the dividing bar 7 for dividing the cavity 8 is usually used. As shown in FIG. 11 (a), 7 is a front end surface of the movable mold 5 so that the molten resin M1 filled in the cavity 8a on one side does not enter the cavity 8b on the other side. Although the resin leakage is prevented by abutting 7b, the sealing pressure by the dividing bar 7 is smaller than the injection pressure 120 kg / cm ^{2 of the} molten resin due to restrictions on the capacity of the dividing bar 7 and the cylinder 7a. In some cases, resin leakage is likely to occur, and a sharp parting line cannot be formed, leading to a decrease in appearance appearance or a loss of resin material.

  Further, as shown in FIG. 11 (b), the joint portion between the door trim upper 2 and the door trim lower 3 is joined only by the thickness of the plate, so that the joint strength is weak, and this portion is applied when an impact is applied. At the same time, it has been pointed out that it is prone to breakage.

  The present invention has been made in view of such circumstances, and is a multicolor molded product and a molding method thereof for molding a multicolor molded product using a molding die provided with a dividing bar for dividing a cavity. An object of the present invention is to provide a multicolor molded product that can maintain a good resin sealing property, reliably avoid resin leakage, and have improved bonding strength between resin molded products, and a molding method therefor.

  Therefore, the present inventors can devise the shape of the upper surface of the dividing bar that divides the cavity to reduce the resin flow rate, eliminate resin leakage, and ensure a large bonding area between adjacent resin molded products. As a result, the present invention has been completed.

  That is, the present invention divides a cavity of a molding die into a plurality of cavities by dividing bars, and injects and fills molten resin into each of the cavities from an injection machine corresponding to each cavity. In an integrated multicolor molded product, the upper surface of the dividing bar is set to have a stepped surface shape that reduces the flow rate of the molten resin filled in the first cavity, thereby causing resin leakage of the molten resin. And a plurality of resin molded products in the multicolor molded product are bonded to each other by an uneven surface matching the stepped surface shape of the upper surface of the dividing bar.

  In this method for molding a multicolor molded product, the cavity of the molding die is partitioned into a plurality of cavities by dividing bars, and then the molten resin is injected and filled into the first cavity, and the resin molded product on one side is formed. Then, 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 put through the parting line formed on the basis of the dividing bar. In a molding method of a multicolor molded product integrated with a resin molded product, a dam function of molten resin filled in the first cavity is achieved on the upper surface of the dividing bar installed in the molding die. By providing the step portion including the stopper wall, when the dividing bar is raised and the molten resin is filled into the first cavity, the molten resin is dammed to the stopper wall, so that the molten resin Flow rate is suppressed And characterized in that it is.

  Here, the multicolor molded product is an integrated product of two or more types of resin molded products of different colors that are molded by the same injection mold. It can be applied not only to two-tone two-color molded products such as luggage trim and trunk trim, but also to automotive interior parts based on multi-color molded products of two or more colors.

  The molds used for molding multicolor molded products are movable molds that can be clamped and opened together, fixed molds, and split bars that divide the cavities formed between the two molds. And a plurality of injection machines that supply molten resin into the divided cavities. The dividing bar performs a predetermined stroke advance / retreat operation by the drive cylinder so as to face the cavity along the parting line of the adjacent molded product. Furthermore, a stepped surface is formed on the upper surface of the dividing bar to gradually reduce the flow rate of the molten resin in the cavity.

  Therefore, according to the present invention, when the molten resin is injected and filled into the first cavity after the molding die is clamped, the molten resin is a step (stopper wall) set on the upper surface of the dividing bar. Since the resin flow velocity is reduced, the sealing performance is improved and the resin leakage can be eliminated. In addition, since only a part of the upper surface of the dividing bar hits the mold surface of the movable mold, it is possible to prevent damage to the drawing pattern of the movable mold as much as possible, and the appearance of the parting line looks good In addition, the damage due to the impact of the movable side mold or the dividing bar can be kept low.

  Furthermore, according to the present invention, since the joint surface shape between the resin molded products is the same as the stepped surface shape provided on the upper surface of the dividing bar, the contact area between the resin molded products compared to the conventional structure. Therefore, the bonding strength can be increased.

  As described above, according to the multicolor molded product according to the present invention, when integrating the resin molded products having different colors using the same molding die, the upper surface of the dividing bar that divides the cavity is made of the resin. By adopting the stepped surface shape that reduces the flow velocity, the joint area between the resin molded products can be obtained with the same joint area as the stepped surface shape, and a large joint area between the two can be secured, and the resin molded products can be parted out. The effect is that the bonding strength of the portion can be maintained firmly.

  Furthermore, according to the molding method of the multicolor molded product according to the present invention, when the resin molded product having different colors is integrated using the same molding die, it is melted on the upper surface of the dividing bar that divides the cavity. Since the flow rate of the resin is set to a stepped surface shape having a plurality of stopper walls that gradually reduce the flow rate of the resin, the resin flow rate is reduced when the molten resin is injected and filled into the first cavity. , The sealing property of the resin is enhanced, the resin leakage does not occur in the cavity on the other side, the parting line can be formed well, the appearance appearance can be maintained well, the material loss is small, and economically Also has the advantage of being advantageous.

  In addition, since the upper surface of the dividing bar is set to have a shape having a plurality of step portions, the number of parts that abut against the mold surface of the movable side mold is small, and the impact and squeezing damage to the movable side mold are kept small. It has the effect of being able to.

  Hereinafter, specific examples of a multicolor molded product and a molding method thereof according to the present invention will be described in detail with reference to the accompanying drawings. Note that the gist of the present invention is as described in the scope of claims, and the contents of the embodiments described below are merely examples of the present invention.

  1 to 8 show an embodiment of the present invention. FIG. 1 is a front view showing a car door trim of an upper and lower split type to which the structure of a multicolor molded product according to the present invention is applied. FIG. FIG. 3 is an overall view showing a molding die used in the molding method of the door trim, FIG. 4 is an explanatory view showing the configuration of a dividing bar in the molding die, and FIGS. It is explanatory drawing which shows the formation process of the door trim upper in the same door trim, and the formation process of a door trim lower, respectively.

  In FIG. 1 and FIG. 2, the automobile door trim 10 is composed of an upper and lower divided body of a door trim upper 20 and a door trim lower 30, and a parting line 11 is set between the door trim upper 20 and the door trim lower 30. Has been. Furthermore, the door trim upper 20 and the door trim lower 30 are made of resin-molded products having different colors so that the accent effect on the appearance can be emphasized, and the product surfaces 20a and 30a of the door trim upper 20 and the door trim lower 30, respectively, The drawn pattern is transferred from a molding die to be described later. The door trim 10 is provided with various accessory parts, for example, an inside handle escutcheon 21 is attached to the door trim upper 20, and an armrest 22 is formed above the parting line 11 for an occupant to rest on the elbow. On the other hand, a door pocket opening 31 is formed in the door trim lower 30, and a speaker grill 32 is provided integrally with or separately from the door trim lower 30 on the front side of the door pocket opening 31. In FIG. 2, reference numeral 33 denotes a pocket back cover, and reference numeral 34 denotes a door panel.

  In the door trim 10 according to the present invention, the appearance performance near the parting line 11 between the door trim upper 20 and the door trim lower 30 is improved, and the bonding strength between the door trim upper 20 and the door trim lower 30 is enhanced. It is a feature. Since the structural features of the door trim 10 are closely related to the method of the present invention, they will be described in detail when the method of the present invention is described.

  Next, the configuration of the molding die 40 for molding the door trim 10 will be described with reference to FIGS. In FIG. 3, the entire configuration of the molding die 40 will be described. The molding die 40 employs an injection molding method, and the movable side die 41 and the fixed side die 42 are clamped to each other. The fixed side mold 42 is provided with injection machines 43a and 43b for supplying the material of the door trim upper 20 and the door trim lower 30, and the door trim upper 20 and the door trim lower 30. A dividing bar 50 having a sealing function for dividing each cavity is arranged.

  More specifically, the movable side mold 41 is formed with a cavity portion 411 that matches the product shape, and the movable side mold 41 is driven by a lifting / lowering cylinder 412 connected to the upper surface of the movable side mold 41. Performs a predetermined stroke up-and-down motion, and the fixed mold 42 is clamped and opened. In addition, guide bushes 413 serving as a guide mechanism are provided at the four corners of the movable mold 41. On the other hand, the fixed side mold 42 is provided with a core part 421 corresponding to the cavity part 411 of the movable side mold 41. Further, manifolds 422a and 422b and gates 423a and 423b are provided to supply molten resin to the mold surface of the core portion 421, and the injection machine passes through the resin passages of the manifolds 422a and 422b and gates 423a and 423b. Molten resins M1 and M2 supplied from 43a and 43b are supplied into the first cavity C1 for door trim upper molding formed on the upper surface of the core portion 421 and into the second cavity C2 for door trim lower molding. . In addition, guide posts 424 serving as a guide mechanism protrude from the four corners of the fixed-side mold 42, and the guide posts 424 are guided into the guide bush 413 when the molding die 40 is clamped. Thus, the pressing posture of the movable mold 41 can be properly maintained. That is, the molten resin M1 supplied from the one-side injection machine 43a is injected and filled into the first cavity C1 for door trim upper molding through the manifold 422a and the gate 423a. On the other hand, the molten resin M2 supplied from the other-side injection machine 43b is injected and filled into the second cavity C2 for door trim lower molding through the manifold 422b and the gate 423b.

  Incidentally, the molding die 40 according to the present invention is characterized by the structure of the dividing bar 50 that divides the cavity C into C1 and C2. That is, as shown in FIG. 4, the dividing bar 50 is formed of an elongated block body along the parting line 11, and the dividing bar 50 is moved up and down by the drive cylinder 51. On the upper surface 52 of the dividing bar 50, three steps 53a, 53b, 53c (encoded sequentially from the inside for convenience of explanation) are formed as shown in the figure. Accordingly, the three-stage step portions 53a, 53b, and 53c are formed by the molten resin colliding with the stopper walls 54a, 54b, and 54c of the respective step portions (53a, 53b, and 53c) at the time of injection filling of the molten resin. The flow rate is reduced.

  And the process of shape | molding the door trim 10 which is a multicolor molded product shown in FIG. 1, FIG. 2 using this shaping die 40 is demonstrated. First, the movable die 41 is lowered by a predetermined stroke by driving the elevating cylinder 412, and the molding die 40 is clamped. Then, the molten resin M1 is injected and filled into the first cavity C1 from the injection machine 43a on one side through the manifold 422a and the gate 423a. At this time, as shown in FIG. The three-stage step portions 53a, 53b and 53c formed on the upper surface 52 of the upper surface 52 are stepped against the stopper walls 54a, 54b and 54c in stages, and the resin flow velocity of the molten resin M1 is decelerated as it goes to the terminal. Since the sealing property is improved, as a result, no resin leakage occurs on the second cavity C2 side, and a good parting line can be formed. At this time, since the abutting surface of the movable side mold 41 and the dividing bar 50 is very small, there is little squeezing damage and less impact when the squeezed pattern is transferred to the movable side mold 41. The durability of the mold can be increased.

  Next, when the molding of the door trim upper 20 is completed, the dividing bar 50 is retracted from the cavity C by the drive of the drive cylinder 51, and as shown in FIG. 7, through the other side injection machine 43b, manifold 422b, and gate 423b. The second cavity C2 is injected and filled with the molten resin M2 on the other side, and the door trim lower 30 is molded into a required shape and integrated with the door trim upper 20, so that the two-tone type door trim 10 shown in FIGS. Is formed. Then, when the molten resin M2 is injected and filled into the second cavity C2, as shown in FIG. 8, the dividing bar 50 is positioned below by the contraction operation of the drive cylinder 51. Since the door trim upper 20 and the door trim lower 30 are joined stepwise in accordance with the shape of the stepped portions 53a and 53b in the dividing bar 50, a large joining area can be secured and the joining strength can be enhanced. In this embodiment, the door trim 10 is manufactured in the form of a two-color molded product. However, for example, a three-color molded product divided into three parts in the vertical direction, such as a trim upper, a trim center, and a trim lower, may be used.

  In the embodiment described above, the present invention is applied to the door trim 10 formed of the upper and lower divided bodies of the door trim upper 20 and the door trim lower 30. However, in addition to the two-color molded product, multicolor molding that provides an accent effect on the appearance. The present invention can be applied to all products. Furthermore, it is possible to appropriately change the shape and the like of the dividing bar 50, and as a modified example of the door trim upper 20, a molded product with a skin can be applied.

It is a front view which shows the door trim for motor vehicles of the upper and lower divided type which is one Example of the multicolor molded product which concerns on this invention. It is the II-II sectional view taken on the line in FIG. It is explanatory drawing which shows the whole structure of the molding die used for shaping | molding of the door trim for motor vehicles shown in FIG. It is explanatory drawing which shows the structure of the division | segmentation bar which divides | segments the cavity in the shaping die shown in FIG. It is explanatory drawing which shows the molding process of the door trim upper in the molding method of the door trim shown in FIG. It is explanatory drawing which shows the positional relationship of the division | segmentation bar in the formation process of the door trim upper shown in FIG. It is explanatory drawing which shows the molding process of the door trim lower in the molding method of the door trim shown in FIG. It is explanatory drawing which shows the positional relationship of the division | segmentation bar in the formation process of the door trim lower shown in FIG. It is a front view which shows the conventional door trim. It is explanatory drawing which shows the structure of the shaping die which shape | molds the conventional door trim. It is explanatory drawing which shows operation | movement of the division | segmentation bar used for shaping | molding of the conventional door trim.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Automotive door trim 11 Parting line 20 Door trim upper 30 Door trim lower 40 Molding die 41 Movable side die 411 Cavity part 412 Lifting cylinder 42 Fixed side die 421 Core part 422a, 422b Manifold 423a, 423b Gate 43a, 43b Injection machine 50 Dividing bar 51 Drive cylinder 52 Upper surface 53a, 53b, 53c Step part 54a, 54b, 54c Stopper wall C1 First cavity (for door trim upper molding)
C2 2nd cavity (for door trim lower molding)
M1, M2 molten resin

Claims (2)

The cavity (C) of the molding die (40) is divided into a plurality of cavities (C1, C2) by the dividing bar (50), and molten resin is injected from the injection machines (43a, 43b) corresponding to the cavities (C1, C2). In the multicolor molded product (10) formed by integrating a plurality of resin molded products (20, 30) by injection filling (M1, M2) into the cavities (C1, C2),
The upper surface (52) of the dividing bar (50) is set to have a stepped surface shape that reduces the flow rate of the molten resin (M1) filled in the first cavity (C1). The resin leakage of M1) is avoided, and the plurality of resin molded products (20, 30) in the multicolor molded product (10) are formed in the stepped surface shape of the upper surface (52) of the dividing bar (50). A multi-color molded product characterized by being joined with matching uneven surfaces. The cavity (C) of the molding die (40) is divided into a plurality of cavities (C1, C2) by the dividing bar (50), and then the molten resin (M1) is injected and filled into the first cavity (C1). Then, after molding the resin molded product (20) on one side, the dividing bar (50) is lowered, and the molten resin (M2) is injected and filled into the second cavity (C2). Molding method of multicolor molded product (10) in which resin molded product (30) is integrated with resin molded product (20) on one side through parting line (11) formed based on dividing bar (50) In
A stopper wall that achieves the weir function of the molten resin (M1) filled in the first cavity (C1) is provided on the upper surface (52) of the dividing bar (50) installed in the molding die (40). Since the step portions (53a, 53b, 53c) having (54a, 54b, 54c) are provided, the dividing bar (50) is raised to allow the molten resin (M1) to enter the first cavity (C1). When filling, the molten resin (M1) is dammed to the stopper walls (54a, 54b, 54c), so that the flow rate of the molten resin (M1) is suppressed, and a method for forming a multicolor molded product .

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