JP2008049603A - Method for manufacturing molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve adhesive strength between a partitioning insert and a hollow part, and to prevent different kinds of molding materials from being mixed together, by positioning the partitioning insert when molding is performed, in a method for manufacturing a molding part for a mold for a weather strip, which partitions a cavity in the mold by the partitioning insert and keeps different kinds of the molding materials injected in respective partitioned cavities. <P>SOLUTION: In the cavity 29 for forming the hollow part for the mold, a root connected to the cavity 28 forming a trim part is gradually widely formed toward the cavity 28, and a contact area between the cavity part and the partitioning insert 33 is increased to increase adhesive force. The partitioning insert 33 is positioned by fitting a pin fitting hole 34 in a pin 32 of a trim mold 23. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a method for manufacturing a molded article formed of different types of molding materials.
The heterogeneous molding material as used in the present invention includes materials with different types of materials, materials with different colors, and materials with different types of materials and colors.

  One of these types of molded products is a molded part of an automobile weather strip. FIG. 1 shows an opening weather strip attached to a door opening edge portion of an automobile body. The extrusion forming portion 1 is integrally connected to the extrusion forming portion 1 and attached to a corner of the door opening edge portion. The mold forming part 2 is formed. In the figure, the triangle marks indicate the molded part 2 on the side of the painted part and the extruded part 1 on the side of the non-filled part. The same applies to the following drawings.

  The above-described extruded portion 1 includes a trim portion 4 in which a core metal 3 having a substantially U-shaped cross section is embedded, and a hollow seal portion 5 formed to protrude from one side surface of the trim portion 4. The trim portion 4 is usually hard. The hollow seal portion 5 is formed of a soft material such as a rubber material or a thermoplastic elastomer, and the hollow seal portion 5 is formed of a soft material such as a soft rubber material or a thermoplastic elastomer, and a sponge material. Also known is a 4 in color.

  As shown in FIG. 2, the mold forming portion 2 is also composed of a trim portion 7 and a hollow portion 8 which are integrally formed continuously with the trim portion 4 and the hollow seal portion 5, and the trim portion 7 is made of a hard material and is also a hollow portion. 8 is formed of a soft material, and when the trim part 4 of the extrusion molding part 1 is colored, the trim part 7 of the mold molding part 2 is also the same color. In this way, when the trim portion 7 and the hollow portion 8 are formed of different materials, there are two types of molds: a mold for forming the trim portion 7 and a mold for forming the hollow portion 8 by inserting the molded trim portion 7. A mold is required and molding is required twice, which increases equipment costs and increases man-hours, resulting in high costs.

Although it is possible to simultaneously inject and mold two types of molding materials into the same mold, different types of molding materials tend to mix at the boundary portion, resulting in a decrease in strength. If the colors are different, the appearance will be worse. In order to cope with this problem, as shown in FIG. 3, the following Patent Document 1 discloses a partition piece 12 at a boundary portion of different molding materials in a cavity 11 in a mold 9 for molding a mold forming portion 2 of an opening weather strip. And the cavity 11 is divided into a cavity 11a for molding the trim part 4 and a cavity 11b for molding the hollow part 8, and different molding materials are injected into the cavities 11a and 11b, respectively. A method of manufacturing the mold part 2 that prevents the molding material from flowing into the cavity is disclosed. In the figure, the arrow indicates the direction in which the molding material flows during molding.
JP 2002-67083 A

  The conventional method for manufacturing a molded article using the partition piece 12 shown in FIG. 3 has the following problems. This will be described with reference to FIG. 4 which is an enlarged view of the part a in FIG. 3. The material for forming the partition piece 12 and the hollow part 8 is a different molding material, and the width d of the connecting part 14 connecting the two is narrow. Therefore, the adhesive strength is weak and there is a possibility of peeling at the connecting portion 14, and the partition piece 12 contacts the mold 9 with the b portion and the c portion, but the contact area is small and the holding force to the mold 9 is weak. In other words, the partition piece 12 may move back and forth and right and left by injection of the molding material.

  An object of the present invention is to provide an adhesive strength between a molded product partition insert and a molded product in a molded product manufacturing method in which a mold cavity is partitioned by a partition insert and different molding materials are injected into each partitioned cavity. In addition, the partitioning insert is firmly positioned in the mold during molding so that the partitioning insert does not move and mixing of different molding materials does not occur.

  The invention according to claim 1 is a method of manufacturing a molded article having a base portion, a branch portion branched from the base portion, and a branched portion formed from a different base material from the base portion, and a mold for molding the molded product The cavity includes a cavity for forming the base, and a cavity connected to the cavity and for forming the branch portion, and prevents a molding material from being mixed in the connecting portion of the cavity for forming the base and the cavity for forming the branch portion. In the above-described manufacturing method in which the partition insert is provided, the cavity for forming the branch portion is formed such that the base connected to the cavity for forming the base portion is gradually widened toward the cavity for forming the base portion. The insert has a flat surface that closes the opening of the maximum width of the base of the cavity forming the branch portion, and is inserted into the mold to restrict lateral movement of the front, rear, left, and right. Is the fact characterized.

  The invention according to claim 2 is a method of manufacturing a molded article having a base portion, a branch portion branched from the base portion, and the branch portion formed from a different molding material. The mold for molding the molded product The cavity includes a cavity for forming the base, and a cavity connected to the cavity and for forming the branch portion, and prevents a molding material from being mixed in the connecting portion of the cavity for forming the base and the cavity for forming the branch portion. In the above-described manufacturing method in which the partition insert is provided, the cavity for forming the branch portion is formed such that the base connected to the cavity for forming the base portion is gradually widened toward the cavity for forming the base portion. The insert has a flat surface that closes the opening of the maximum width of the base of the cavity for forming the branch portion, and the mold and the partition in contact with the partition insert With locating pins in one of use inserts are more protruded at appropriate intervals, the pin on the other, characterized in that the pin fitting hole to be fitted is formed with a plurality.

  The invention according to claim 3 is characterized in that, in the invention according to claim 1 or 2, the molded article is a weather strip for automobiles, the base portion constitutes a trim portion, and the branch portion constitutes a hollow portion.

  According to the invention according to claim 1, the root of the branch portion of the molded product is formed so that the cross section gradually becomes wider toward the base, and is connected to the partition insert at the maximum width thereof. Since the contact area with the insert increases, the adhesive force increases, making it difficult to peel off, and the partition insert is fitted into the mold to restrict front / rear and left / right movements, so that the partition insert at the time of molding Can prevent the mixing of different molding materials.

  According to the invention according to claim 2, as in the invention according to claim 1, the adhesive force between the branch portion and the partition insert can be increased, and the partition insert is formed wide, so that FIG. In the conventional partition piece 12 shown, it is possible to project a positioning pin that could not be formed due to its narrow width, or to form a pin fitting hole into which the pin is fitted. By forming the pin and the pin fitting hole, the partitioning insert is firmly positioned in the mold, thereby preventing the partitioning insert from moving freely during molding and preventing mixing of different molding materials.

  According to the invention of claim 3, the effect of the invention of claim 1 or 2 described above can be achieved when the weather strip is formed.

  Hereinafter, the manufacturing method of the weather strip for motor vehicles of embodiment of this invention is demonstrated with reference to drawings. In the figure, the same reference numerals are assigned to the same structural parts as those of the weather strip shown in FIGS.

  FIG. 5 shows a mold for forming the mold forming portion 30 of the weather strip shown in FIG. 9. The fixed lower mold 21, the upper mold 22 that opens and closes by raising and lowering, and the molds 21 and 22 are interposed. Trim molds 23 and 24, a core mold 25 that forms a hollow portion, and a slide mold 26 that moves back and forth to the left and right. A cavity 27 is formed by each of the molds 21 to 26, and the cavity 27 is a substantially U-shaped base. A cavity 28 that forms a cross-sectional trim part and a cavity 29 that is connected to the cavity 28 and forms a hollow part that is a bifurcation part, and the root of the cavity 29 connected to the cavity 28 is directed toward the cavity 28. The cross section is gradually formed wider. As shown in FIGS. 6 and 7, the trim mold 23 facing the opening of the cavity 29 at the base of the cavity 28 protrudes from the pin base 31 and the pin base 31 and forms a convex cross section together with the pin base 31. A plurality of positioning pins 32 are attached at appropriate intervals along the curved edges, and curved plate-like partitioning inserts 33 shown in FIG. Can be installed.

  In the illustrated example, the pin 32 is attached to the trim mold 23 and the pin fitting hole 34 is formed in the partition insert 33. However, the pin 32 is attached to the partition insert 33 and the pin fitting hole 34 is trimmed. 23 can also be formed. Further, the pin 32 may be attached to the core die 25 facing the cavity 28.

  As described above, the partitioning insert 33 attached to the trim mold 23 along the curved edge closes the opening of the maximum width at the base of the cavity 29 as shown in FIG. The molding material is made of rubber or olefin-based thermoplastic elastomer TPO injected into the cavity 28 through the same color as the colored hard trim portion 4 of the extruded portion 1, and a runner 37 from another gate (not shown). The soft molding material made of the soft rubber or the olefin-based thermoplastic elastomer TPO injected into the cavity 29 through the mixing is prevented from being mixed.

  For example, when the olefin-based thermoplastic elastomer TPO is used as the molding material, the partitioning insert 33 described above is a resin such as the same olefin-based thermoplastic elastomer TPO, styrene-based elastomer TPS, polypropylene PP, polyethylene PE, polystyrene PS, or iron, In the case where the molding material is rubber such as EPDM, for example, it is formed of the above-described metal. In addition, when the partition insert 33 is made of metal, an adhesive is applied to the bonding surface because it is not fused with the molding material.

  FIG. 9 is obtained by using the mold shown in FIG. 5, attaching the partition insert 33 to the trim mold 23, attaching the extrusion molding part 1 to the mold, and then injection-molding a molding material into the cavity 27. FIG. 10 shows a section 30 of the weather strip which is a molded product, and the partition insert 33 is shown in FIG. 10 which is a section taken along the line CC of FIG. 9 and FIG. 11 which is a section taken along the line DD. It connects with the hollow part 8 as a branch part, and comprises the one side wall of the trim 4 which makes the substantially U-shaped cross section which is a base part.

  According to the method for producing a weatherstrip molded part of the present embodiment, the root of the hollow part 8 connected to the partitioning insert 33 has a large contact area with the partitioning insert 33, so that the adhesive force increases. The separation insert 33 is wide, so that the pin fitting hole 34 can be formed, and the strength is not impaired even if the pin fitting hole 34 is formed. By inserting the pin fitting hole 34 into the pin 32, the partitioning insert 33 is positioned, and the partitioning insert 33 can be positioned in a fixed state by preventing the partitioning insert 33 from moving at the time of molding, thereby reliably preventing the mixing of different molding materials. The effect of being able to do is produced.

  FIG. 12 shows another embodiment of the mold and the partition insert. This mold is different from the mold shown in FIG. 5 in that the pins 32 attached to the trim mold 23 are omitted. Further, the difference between the partition insert 41 and the partition insert 33 is that the partition insert 41 is formed wider than the partition insert 33, and one side edge thereof is inserted between the trim mold 23 and the center mold 25 to be positioned and supported. The other side edge is positioned by the slide mold 26, and the front and rear ends abut against the extruded portion 1, so that the front and rear and right and left movements are restricted and supported by the one side edge.

  FIG. 13 shows a cross-sectional structure of a molded portion of a weather strip formed using the mold shown in FIG. 12, and the partition insert 41 is provided over almost the entire length of one side wall of the trim portion 4.

  The present invention is not limited to a weather strip provided with a trim portion and a hollow portion, and is generally applied to a molded article including a molded portion formed of different molding materials.

Plan view of the main part of a conventional weather strip with the extrusion part cut away AA line sectional view of FIG. Sectional drawing of the principal part of the metal mold | die which manufactures the shaping | molding part of another conventional weather strip Enlarged sectional view of part a of the mold shown in FIG. Sectional drawing of the principal part of the metal mold | die used with this invention method The top view of the principal part of the trim mold of the metal mold shown in FIG. BB expanded sectional view of FIG. Plan view of partition insert The top view of the principal part of the weather strip obtained by this invention CC sectional view of FIG. Sectional view along line DD Sectional drawing of the principal part of the metal mold | die which attached the partitioning insert of another aspect Sectional drawing of the molding part of the weather strip manufactured using the metal mold | die shown in FIG.

Explanation of symbols

1 .. Extrusion molding part 2, 30.. Mold molding part 3. Core metal 4, 7. Trim part 5. Hollow seal part 8 Hollow part 9 Mold 11, 27, 28, 29 · Cavity 12 · · Partition piece 21 · · Lower die 22 · · Upper die 23 and 24 · · Trim die 25 · · Core die 26 · · Slide die 31 · · Pin base 32 · · Pins 33 and 41 for positioning ..Partition insert 34..Pin fitting holes 36, 37..Runway

Claims (3)

  A method of manufacturing a molded article having a base portion 7 and a branch portion 8 branched from the base portion 7 and formed from a different molding material. The cavity 27 of the mold 9 for molding the molded product. Includes a cavity 28 for forming the base 7, and a cavity 29 connected to the cavity 28 for forming the branch 8, and a connecting portion between the cavity 28 for forming the base 7 and the cavity 29 for forming the branch 8 includes: In the above-described manufacturing method in which the partition insert 41 for preventing the mixing of the molding material is provided, the cavity 29 for molding the branch portion 8 is a cavity 28 in which the root connected to the cavity 29 for molding the base portion 7 molds the base portion 7. The partition insert 41 has a flat surface that closes the opening of the maximum width of the root of the cavity 29 for forming the branching portion 8. And, and a manufacturing method of a molded article, characterized in that the movement of the left and right sides before and after being fitted in the mold 9 is restricted.   A method of manufacturing a molded article having a base portion 7 and a branch portion 8 branched from the base portion 7 and formed from a different molding material. The cavity 27 of the mold 9 for molding the molded product. Includes a cavity 28 for forming the base 7, and a cavity 29 connected to the cavity 28 for forming the branch 8, and a connecting portion between the cavity 28 for forming the base 7 and the cavity 29 for forming the branch 8 includes: In the above-described manufacturing method in which the partition insert 33 for preventing the mixing of the molding material is provided, the cavity 29 for molding the branch portion 8 is a cavity 28 in which the root connected to the cavity 28 for molding the base portion 7 molds the base portion 7. The partition insert 33 has a flat surface that closes the opening of the maximum width of the root of the cavity 29 for forming the branching portion 8. In addition, a plurality of positioning pins 32 protrude at an appropriate interval on either one of the mold in contact with the partitioning insert 33 and the partitioning insert, and the other is a pin fitting hole 34 into which the pin is fitted. A method for producing a molded product, characterized in that a plurality of is formed.   The method for producing a molded product according to claim 1 or 2, wherein the molded product is a weather strip for an automobile, the base portion constitutes a trim portion 7, and the branch portion constitutes a hollow portion 8.

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