JPWO2018008484A1 - Mold and method of manufacturing two-color molded article - Google Patents

Abstract

  The mold is a mold 50 used when manufacturing a two-color molded article, and includes a first mold 52 and a second mold 54 to be combined with the first mold. The first mold 52 and the second mold 54 communicate with the first cavity C1 according to the shape of the primary molded product, which is formed in a combined state, and the first cavity, and the first mold and the second mold And a non-contact area R1 not in contact with the mold. A noncontact region R1 has a gap G of such a size that the first resin material filled in the first cavity C1 does not enter.

Description

  The present invention relates to a mold and a method of manufacturing a two-color molded article.

  Conventionally, as a method of injection molding, a technique is known in which a primary molded article is formed and then a secondary molded article is formed around the primary molded article to produce a two-color molded article. The technique of two-color molding is used, for example, when producing a translucent cover of a lamp such as a headlamp of a vehicle (see Patent Document 1).

JP, 2014-176974, A

  In the case of producing the above-mentioned two-color molded article, there are occasions where a part of a mold used in the process of producing the primary molded article is also used in the process of producing the secondary molded article. Commonly used molds may be damaged by contact with other molds in the process of making a primary molded article, and the damaged part may be secondary in the process of making a secondary molded article. Transfer to the surface of the molded article contributes to the appearance defect.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a technique for reducing appearance defects in a two-color molded article.

  In order to solve the above problems, a mold according to an embodiment of the present invention is a mold used when manufacturing a two-color molded article, and a first mold and a second mold to be combined with the first mold. And. The first mold and the second mold are formed in combination, and are in communication with the first cavity according to the shape of the primary molded product, the first cavity, and the first mold and the second mold. Is a non-contact area which is not in contact with the non-contact area, and the non-contact area having a gap of a size such that the first resin material filled in the first cavity does not enter.

  According to this aspect, when forming the primary molded product, the first mold and the second mold do not contact not only in the first cavity but also in the non-contact area, so that the first metal sandwiching the non-contact area Scratches are less likely to occur on the surface of the mold and the second mold.

  It may further comprise a third mold in combination with the first mold. The first mold and the third mold are configured to have a second cavity corresponding to the shape of the secondary molded article formed in a combined state, and the second cavity is at least at a non-contact area. Some may be included. As described above, the surface of the first mold and the second mold sandwiching the non-contact area is unlikely to be scratched. Therefore, when forming the secondary molded product, the situation where the scratch of the first mold is transferred to the surface of the secondary molded product is suppressed.

  The second cavity is shaped to form a flange surface of the secondary molded product and an upright wall surface intersecting with the flange surface, and a parting line between the first mold and the third mold is formed along the flange surface It may be done. Thereby, the parting line in the secondary molded product can be made inconspicuous.

  The non-contact area is such that the width of the gap at the end communicating with the first cavity is smaller than the width of the gap near the center of the non-contact area. This makes it difficult for the first resin material to infiltrate the noncontact region.

  Another aspect of the present invention is a method of producing a two-color molded article. This method combines a first mold and a second mold to form a first cavity and a non-contact area in communication with the first cavity and in which the first mold and the second mold do not contact. The step of forming, the step of injecting the first resin material into the first cavity, the step of replacing the second mold with the third mold, and the second step by combining the first and third molds. Forming a cavity; and injecting a second resin material into the second cavity. The non-contact area has a gap sized so that the first resin material filled in the first cavity does not enter. The second cavity includes at least a portion of the non-contact area.

  According to this aspect, when forming the primary molded product, the first mold and the second mold do not contact not only in the first cavity but also in the non-contact area, so that the first metal sandwiching the non-contact area Scratches are less likely to occur on the surface of the mold and the second mold. In addition, when forming the secondary molded product, the situation in which the scratch of the first mold is transferred to the surface of the secondary molded product is suppressed, so that appearance defects in the two-color molded product can be reduced.

  It is to be noted that any combination of the above-described components, and a conversion of the expression of the present invention among methods, apparatuses, systems, and the like are also effective as an aspect of the present invention.

  According to the present invention, appearance defects in a two-color molded article can be reduced.

It is a front view which shows the example which applied the two-color-molding goods which concern on 1st Embodiment to the translucent cover of the headlamp provided in the vehicle body front part. FIG. 2A and FIG. 2B are diagrams schematically showing the process of forming each resin portion in the cross section A-A of the light transmitting cover 100 shown in FIG. 1 including a mold. FIG. 3A and FIG. 3B are diagrams schematically showing the process of forming each resin portion in the A-A cross section of the light transmitting cover 100 shown in FIG. 1 including a mold. It is the figure which showed typically each resin part in the BB cross section of the light transmission cover 100 shown in FIG. 1 including a metal mold | die. It is the figure which showed a part of CC cross section of the light transmission cover 100 shown in FIG. It is sectional drawing of the state which combined the 1st metal mold which concerns on 2nd Embodiment, and a 2nd metal mold. It is sectional drawing of the state which combined the 1st metal mold which concerns on 3rd Embodiment, and a 2nd metal mold. It is a schematic diagram which shows the principal part of the positioning mechanism of the 1st metal mold | die and 2nd metal mold | die which concerns on 4th Embodiment. It is sectional drawing of the state which combined the 1st metal mold which concerns on 5th Embodiment, and a 2nd metal mold.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings and the like. In the description of the drawings, the same elements will be denoted by the same reference symbols, and overlapping descriptions will be omitted as appropriate.

First Embodiment
FIG. 1 is a front view showing an example in which the two-color molded article according to the first embodiment is applied to a translucent cover of a headlamp provided at the front of a vehicle body. The translucent cover 100 shown in FIG. 1 is used for a headlamp for the right side.

  The translucent cover 100 is a two-color molded article according to the present embodiment, and is manufactured by a method described later. More specifically, the light transmitting cover 100 includes a light transmitting resin portion 102 formed of a colorless and transparent light transmitting resin, and a black resin 104 laminated in the thickness direction on at least a part of the outer edge of the light transmitting resin portion 102. , Are integrally molded.

  Next, a method of manufacturing a two-color molded article and a mold according to the first embodiment will be described. 2 (a), 2 (b), 3 (a) and 3 (b) show a process of forming each resin portion in the A-A cross section of the light transmission cover 100 shown in FIG. It is the figure typically shown including.

  The mold 50 according to the present embodiment includes a first mold 52 and a second mold 54 to be combined with the first mold 52. As shown in FIG. 2A, the first mold 52 and the second mold 54 are formed in a combined state, a first cavity C1 according to the shape of the primary molded product, and a first cavity C1. And a non-contact area R1 in which the first mold 52 and the second mold 54 are not in contact with each other.

  By using the first mold 52 and the second mold 54 as shown in FIG. 2 (a) in combination, when forming the primary molded article 12, not only in the first cavity C1 but also in the non-contact area R1. Also, since the first mold 52 and the second mold 54 do not contact each other, the surface of the first mold 52 and the second mold 54 which sandwich the non-contact area R1 is less likely to be damaged.

  Next, as shown in FIG. 2B, the first resin material 10 is injected into the first cavity C1. At this time, the noncontact region R1 has a gap G of such a size that the first resin material 10 filled in the first cavity C1 does not enter. This makes it difficult for the first resin material 10 to infiltrate into the non-contact area R1.

  The gap G may be appropriately changed depending on the material of the first resin material 10, for example, the viscosity and fluidity of the molten resin, surface tension with the mold, adhesion to the mold, etc. Specifically, 0. It is 5 mm or less, preferably 0.3 mm or less, more preferably 0.2 mm or less. For example, in the case of using a polycarbonate resin as the first resin material 10, the gap G is preferably 0.2 mm or less. Moreover, when using acrylic resin, ASA (acrylate styrene acrylonitrile) resin, and ABS (Acrylonitrile Butadiene Styrene) resin as the 1st resin material 10, it is preferable that the clearance gap G is 0.10 mm or less. When PBT (Polybutylene terephthalate) resin or polypropylene resin is used as the first resin material 10, the gap G is preferably 0.05 mm or less.

  The lower limit of the gap G is not particularly limited as long as the non-contact region R1 can be formed when the first mold 52 and the second mold 54 are combined, and it may be larger than 0 mm. If it considers, it is 0.01 mm or more, Preferably, it is 0.03 mm or more, More preferably, it is 0.05 mm or more.

  The first resin material 10 filled in the first cavity C1 is then solidified to form a primary molded article 12 having a predetermined shape (see FIG. 3A). At this stage, the second mold 54 is replaced with a third mold 56, and the third mold 56 and the first mold 52 are combined. The first mold 52 and the third mold 56 are configured to have a second cavity C <b> 2 formed in combination, according to the shape of the secondary molded product. The second cavity C2 includes at least a part of the non-contact area R1.

  Next, as shown in FIG. 3A, the second resin material 14 is injected into the second cavity C2. The second resin material 14 filled in the second cavity C2 is then solidified to form a secondary molded article 16 having a predetermined shape (see FIG. 3B). As described above, the surfaces S1 and S2 of the first mold 52 and the second mold 54 sandwiching the non-contact area R1 are not easily damaged. Therefore, when the secondary molded product 16 is formed, a situation in which a flaw on the surface S1 of the first mold 52 is transferred to the surface of the secondary molded product 16 is suppressed, and appearance defects in the two-color molded product are reduced. it can.

  The second cavity C2 is shaped to form an upright wall surface 16b that intersects the flange surface 16a and the flange surface 16a of the secondary molded product 16 (see FIGS. 3A and 3B). Further, parting lines PL of the first mold 52 and the third mold 56 may be formed along the flange surface 16a. In other words, the parting line PL extends from the edge of the flange surface 16a in a direction substantially parallel to the flange surface 16a. Thereby, the parting line PL in the secondary molded product 16 can be made inconspicuous.

  FIG. 4: is the figure which showed typically each resin part in the BB cross section of the light transmission cover 100 shown in FIG. 1 including a metal mold | die. The process of forming the primary molded article 18 and the secondary molded article 20 shown in FIG. 4 is the same as the process of forming the primary molded article 12 and the secondary molded article 16 according to the first embodiment. Therefore, the explanation is omitted.

  The secondary molded product 20 shown in FIG. 4 is a part of the cross section B-B in FIG. Therefore, when the translucent cover 100 is applied to a headlamp for a vehicle, for example, when the hood at the front of the vehicle is opened, the secondary molded product 20 can be visually recognized, so the appearance of the secondary molded product 20 is important.

  Similar to the first mold 52 shown in FIG. 3B, the surface S1 of the first mold 58 is less likely to be scratched. Therefore, when the secondary mold 20 is formed by combining the first mold 58 and the third mold 60, the flaw on the surface S1 of the first mold 58 is transferred to the surface of the secondary mold 20. Such situations are suppressed. Therefore, when the light transmitting cover 100 is applied to a headlamp, it is possible to suppress the appearance of flaws in the appearance and to reduce appearance defects of the two-color molded article.

  FIG. 5 is a view showing a part of a cross section C-C of the light transmitting cover 100 shown in FIG. While the secondary molded product 16 shown in FIG. 3 has the flange surface 16 a and the upright wall surface 16 b, the secondary molded product 24 constitutes a part of the upper surface of the light transmitting cover 100. The steps of forming the primary molded article 22 and the secondary molded article 24 shown in FIG. 5 are the same as the steps of forming the primary molded article 12 and the secondary molded article 16 according to the first embodiment. Therefore, the explanation is omitted.

  The secondary molded article 24 shown in FIG. 5 is a part of a cross section taken along the line C-C in FIG. Therefore, when the light transmitting cover 100 is applied to a headlamp for a vehicle, the secondary molded product 24 can be visually recognized in a state of being attached to the vehicle main body, so the appearance of the secondary molded product 24 is important.

  Similar to the first mold 52 shown in FIG. 3B, the surface S1 of the first mold 62 is less likely to be damaged. Therefore, when the secondary mold 24 is formed by combining the first mold 62 and the third mold 64, the flaw on the surface S1 of the first mold 62 is transferred to the surface of the secondary mold 24. Such situations are suppressed. Therefore, when the light transmitting cover 100 is applied to a headlamp, it is possible to suppress the appearance of flaws in the appearance and to reduce appearance defects of the two-color molded article.

Second Embodiment
FIG. 6 is a cross-sectional view of a state in which the first mold 66 and the second mold 68 according to the second embodiment are combined. In the non-contact area R1 shown in FIGS. 2A and 2B, the gap G was constant over the entire area. However, the non-contact area R1 may be such that the gap G is narrowed by a certain range R2 from the portion communicating with the first cavity C1, and the gap may be wider on the back side. The range R2 is preferably 3 mm or more.

Third Embodiment
FIG. 7 is a cross-sectional view of a state in which the first mold 70 and the second mold 72 according to the third embodiment are combined. In a state in which the first mold 70 and the second mold 72 are combined, the adjustment unit 70 a abuts on the adjustment unit 72 a provided in the second mold 72. The adjusting unit 70a and the adjusting unit 72a are provided to face each other with the non-contact region R1 interposed therebetween. Preferably, the adjusting unit 70a may be provided at a portion where the designability is low.

  Hardened steel (SKD11) is used as the adjusting unit 72a and the adjusting unit 70a, and the adjusting unit 72a is harder than the adjusting unit 70a. As a result, the surface of the adjustment unit 72a is not easily scratched.

Fourth Embodiment
FIG. 8 is a schematic view showing the main part of the positioning mechanism of the first mold and the second mold according to the fourth embodiment. If the tolerances of the molds and the molds are shifted and combined, there is a possibility that the first mold and the second mold come in contact with each other in a part of the non-contact region R1. Therefore, as shown in FIG. 8, the convex portion 74 provided on the first mold is inserted into the concave portion 76 provided on the second mold and positioned, whereby the first metal is formed in the non-contact region R1. Contact between the mold and the second mold is prevented.

Fifth Embodiment
FIG. 9 is a cross-sectional view of a state in which the first mold 78 and the second mold 80 according to the fifth embodiment are combined. When the first resin material 82 is injected into the first cavity C1 formed in a state where the first mold 78 and the second mold 80 are combined to form a primary molded product, the first resin material 82 is formed. Through the gap G to reach the non-contact area R1. When the resin decomposition gas stagnates in the non-contact area R1, it may solidify and adhere to the surface of the first mold 78. Such a deposit may be mixed as foreign matter into the surface or the inside of the secondary molded product when forming the secondary molded product.

  Therefore, in the first mold 78 according to the fifth embodiment, the gas discharge path 84 is provided in the region R3 opposite to the first cavity C1 with the non-contact region R1 interposed therebetween. Thereby, it is possible to prevent the resin decomposition gas of the first resin material 82 from staying in the non-contact region R1, and to suppress the generation of foreign matter caused by the solidification of the resin decomposition gas. The gas discharge passage 84 may be provided on the second mold 80 side.

  The present invention has been described above based on the embodiments. It is understood by those skilled in the art that each of the embodiments is an exemplification, and that various modifications can be made to the combinations of the respective components and processing processes, and such modifications are also within the scope of the present invention. It is a place.

  C1 first cavity, R1 non-contact area, S1 surface, C2 second cavity, R2 range, R3 area, 10 first resin material, 12 primary molded article, 14 second resin material, 16 secondary molded article, 16a flange surface, 16b upright wall surface, 18 primary molded article, 20 secondary molded article, 50 mold, 52 first mold, 54 second mold, 56 third mold, 70 first mold, 70a adjustment Part, 72 second mold, 72a adjustment part, 74 convex part, 76 concave part, 78 first mold, 80 second mold, 82 first resin material, 84 gas discharge path, 100 translucent cover, 102 transparent Photo resin part, 104 black resin.

  The present invention can be used for a mold and a method for producing a two-color molded article.

Claims (10)

A mold used for producing a two-color molded article,
The first mold,
And a second mold combined with the first mold,
The first mold and the second mold are
A first cavity according to the shape of the primary molded article formed in a combined state;
A non-contact area in communication with the first cavity and not in contact with the first mold and the second mold, and having a size such that the first resin material filled in the first cavity does not enter A non-contact area with a gap of
Configured to have
A mold characterized by It further comprises a third mold combined with the first mold,
The first mold and the third mold are
Configured to have a second cavity according to the shape of the secondary molded product, which is formed in a combined state,
The mold according to claim 1, wherein the second cavity includes at least a part of the non-contact area. The second cavity is shaped to form a flange surface of the secondary molded product and an upright wall surface intersecting with the flange surface,
The mold according to claim 2, wherein a parting line of the first mold and the third mold is formed along the flange surface.   The said clearance gap is 0.01-0.5 mm, The metal mold | die of any one of the Claims 1 thru | or 3 characterized by the above-mentioned.   4. The noncontacting region according to any one of claims 1 to 3, wherein the width of the gap at the end portion in communication with the first cavity is smaller than the width of the gap near the center of the noncontacting region. Mold according to item 1.   The mold according to claim 5, wherein the gap between the end portions is 0.01 to 0.5 mm.   The mold according to claim 6, wherein the range in which the gap between the end portions is 0.01 to 0.5 mm is 3 mm or more from a portion in communication with the first cavity. A first mold and a second mold are combined to form a first cavity and a non-contact area in communication with the first cavity and in which the first mold and the second mold do not contact. Process,
Injecting a first resin material into the first cavity;
Replacing the second mold with a third mold;
Forming a second cavity by combining the first mold and the third mold;
Injecting a second resin material into the second cavity;
Including
The non-contact area has a gap of a size such that the first resin material filled in the first cavity does not enter.
The second cavity includes at least a portion of the non-contact area,
A method of producing a two-color molded article characterized in that   The method according to claim 8, wherein the gap is 0.01 to 0.5 mm.   The first resin material is a resin selected from the group consisting of polycarbonate resin, acrylic resin, ASA (acrylate styrene acrylate) resin, ABS (acrylonitrile butadiene styrene) resin, PBT (polybutylene terephthalate) resin, and polypropylene resin The manufacturing method of the two-color-molding goods of Claim 8 or 9 characterized by these.

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