JPH1170544A - Manufacture of weatherstrip for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a weatherstrip having a fine protrusion and recess pattern in an overall length with high productivity by connecting the weatherstrip of extrusion molding by a mold molding. SOLUTION: The method for manufacturing a weatherstrip 1 for an automobile comprises the steps of opposing ends of weatherstrips 1A, 1B extrusion molded and each formed with protrusion and recess shaped embossed pattern S1 on its surface, setting it in a cavity of a mold formed with an embossed pattern on its molding surface, and injecting olefin thermoplastic elastomer mixed with release agent to mold a mold molding connecting part 1C having the pattern S1 on its surface, thereby manufacturing the weatherstrip 1 having the pattern S1 .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a weatherstrip used in an automobile, and more particularly to a method for manufacturing a weatherstrip in which an extruded weatherstrip is connected in series by molding.

[0002]

2. Description of the Related Art A typical example of this type of weather strip is a weather strip which is mounted along the edge of a door opening of a vehicle body. The weather strip is generally obtained by extruding rubber such as ethylene propylene rubber (EPDM). However, at the corner of the door opening edge, particularly at the corner having a curvature close to a right angle, the extruded linear shape is obtained. Since it is difficult to bend the weather strip along the corners, means for dividing the extruded weather strip and connecting the ends of the divided weather strip by molding are employed. I have. In this case, the end of the extruded weather strip to be connected is set facing the cavity of the corner-shaped mold, and rubber of the same type as the rubber of the extruded weather strip is injected into the cavity and added. By the vulcanization, a corner portion connecting the weather strip is formed. In order to improve the releasability of the formed corner portion, a release agent is generally applied to the molding surface of the cavity.

[0003]

However, since the mold release agent applied to the cavity adheres to the surface of the molded corner portion, the color tone of the extruded portion and the surface are considerably different, and the weather Lack of unity of the entire strip.
It is also conceivable to add a release agent in advance to the rubber to be molded.However, due to the high heat applied to the mold to vulcanize the rubber, the release agent is filled into the cavity. It elutes from the inside to the surface, and deteriorates the surface appearance of the molded corner. When the release agent elutes at the connection end with the extruded portion, the bonding strength is reduced.

On the other hand, in order to obtain a sense of unity between the extruded part and the molded part, fine uneven patterns are formed on the surface of the extruded weather strip, and the above-mentioned imprint pattern is formed on the molding surface of the cavity. The corner portion may be molded using a mold having the same grain pattern, and a means of giving a sense of unity to the entire length of the weather strip by a series of grain patterns may be used.

However, it is necessary to periodically reapply the release agent to the textured surface of the cavity. In this case, a new release agent is applied after removing the remaining release agent once. It is extremely difficult to remove it, and the grain surface gradually becomes clogged, and the desired grain pattern does not appear on the molded part.

As another typical example of a weather strip in which terminals of an extruded weather strip are connected by molding, there is a door weather strip attached along the outer periphery of a door frame of an automobile door.

[0007] Door weather strips are generally made of sponge rubber. Since the sponge rubber is flexible, it is possible to bend the extruded weather strip at right angles along the corners of the door frame, but if it is bent, it will be greatly deformed so that the cross-sectional shape is broken. Therefore, an extruded weather strip is connected by molding at a corner portion in the same manner as the above-mentioned weather strip (hereinafter, referred to as an opening weather strip) attached along the door opening of the vehicle body. In this case, like the extruded rubber, in the cavity of the mold with the mold release agent applied to the molding surface,
Rubber injected with a foaming agent is injected and injected.

However, since the rubber filled in the cavity is pressed against the molding surface of the cavity, the surface of the molded corner does not become an uneven sponge skin surface like an extruded part, but is smooth. It becomes a state close to the surface. Therefore, as in the case of the opening weather strip, it is conceivable to form the molding surface of the cavity of the mold on the same uneven surface as the surface skin of the sponge rubber. However, when a mold release agent is applied to the concave-convex molding surface of the cavity, the fine concave portions are almost completely filled with the mold release agent, and the surface of the transferred mold molding corner portion is also almost a flat surface, and it is in a state similar to the extrusion molding portion. Lack of oneness. On the other hand, if a mold release agent is compounded in the rubber for molding, the same problem as in the case of the above-mentioned opening weather strip occurs.

In view of the above-mentioned circumstances, the present invention relates to an extruded weatherstrip having a fine uneven surface, which is connected to a molding connection portion having the same fine uneven surface as the entire surface thereof. It is an object of the present invention to obtain a weatherstrip having a sense of unity and to easily form a mold connecting portion from a mold without applying a mold release agent to the mold.

[0010]

SUMMARY OF THE INVENTION According to the present invention, a terminal of a weather strip made of rubber extruded and having a fine uneven surface is formed in a cavity of a mold having the same uneven surface as the above uneven surface. Inject the olefin-based thermoplastic elastomer containing the release agent into the cavity, and connect the extruded weather strip to the cavity via the molded part with the fine irregularities transferred to the surface. Features (Claim 1).

[0011] Like an opening weather strip,
In the case of a weatherstrip with an uneven grain pattern formed on the surface, a mold with a grain pattern formed on the molding surface of the cavity is used, and an olefin-based thermoplastic elastomer mixed with a release agent is injected into this mold and connected. A part is formed (claim 2).

In connection with a weather strip formed by extruding a fine irregular surface made of sponge rubber like a door weather strip, the molding surface of the cavity is formed to be the same irregular surface as the surface of the sponge rubber material. Using a mold, an olefin-based thermoplastic elastomer mixed with a release agent is injected into the mold to form a mold connection (Claim 3).

Since the mold release agent is added to the molding material, it is not necessary to apply the mold release agent to the mold, and the uneven surface of the mold is not clogged. In addition, since the olefin-based thermoplastic elastomer is molded in a relatively low temperature mold of 100 ° C. or less and does not require vulcanization unlike a rubber material, the release agent contained in the molding material at the time of molding by the heat of the mold is reduced. It does not elute on the surface. Further, the olefin-based thermoplastic elastomer has excellent adhesiveness to EPDM rubber usually used for weather strip.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to the production of an opening weather strip to be mounted along the edge of a door opening on the side of a vehicle body will be described.

As shown in FIG. 1, the opening weather strip 1 has a mounting base 11 having a U-shaped cross section which is mounted along a flange 3 formed at the door opening edge, and a mounting base 11.
The seal portion 12 protrudes from one of the side walls and presses the outer peripheral edge of the closed door. The corners of the opening weather strip 1 are formed by connecting the extruded weather strips 1A and 1B in series through a molding connection 1C that bends at a substantially right angle.

Each of the extruded weather strips 1A, 1B
The mounting base 11 is made of EPDM solid rubber, and the seal portion 12 is made of EPDM sponge rubber. A core material 13 composed of a number of divided core material pieces is provided in the mounting base 11.
Are embedded, and a holding lip 14 sandwiching the flange 3 extends from the inner facing surface.

Extrusion weather strips 1A, 1B
Have substantially the same cross-sectional shape, and are integrally extruded together with the core material 13 in a form in which the mounting base 11 has a flat plate shape. In the process of pulling out the extruded weather strips 1A and 1B, a crimping roller is pressed against the surface side of the mounting base 11 to transfer a crimp pattern. Subsequently, the rubber is vulcanized through a vulcanization tank. After passing through the vulcanizing tank, the flat mounting base 11 is bent into a U-shaped cross section by a bending roller, and finally the weather strips 1A and 1B are cut into a predetermined length.

Next, each extruded weather strip 1A,
1B is formed and connected to a substantially right-angled corner shape by a mold. FIG. 1B shows a cross section of the molded connection portion 1C. 1
5 is a groove into which the flange 3 is inserted. On the molding surface of the cavity of the mold to be used, a grain having the same pattern as that of the extruded weather strips 1A and 1B is formed. The ends of the extruded weather strips 1A and 1B are set at both ends of a cavity of a mold that bends into a corner shape. Pigments of the same type as in 1A, 1B, and further a release agent,
For example, zinc stearate is added, and an olefin-based thermoplastic elastomer melted at about 150 ° C. is injection-filled into a mold cavity having a mold temperature of about 60 ° C. The mixing ratio of the release agent in the injection material is about 2 to 10% by weight.

The injected elastomer is cooled, and the extruded weather strips 1A and 1B are formed into a molded connection portion 1 on which a grain pattern identical to the grain pattern formed thereon is transferred.
Connected by C. At the time of molding, the thermoplastic elastomer enters into fine concave portions on the end faces of the extruded weather strips 1A and 1B and is welded, so that the molded part and the extruded part are firmly joined. Also, since the temperature of the elastomer at the time of molding is much lower than the rubber vulcanization temperature, the release agent in the elastomer elutes to the surface to inhibit the bonding with the extruded part, or It does not affect the color tone of the surface of the molded part.

In this manner, the opening weather strip 1 to be mounted along the opening edge of the door of the vehicle body is obtained by molding and connecting the extruded weather strips 1A and 1B to each other. The series in the same emboss pattern design S ₁ is formed on the mounting base portion 11 of the opening weather strip 1, as shown in FIG. 1 (A).

The material of the extruded weather strip may be an olefin-based, styrene-based, or urethane-based thermoplastic elastomer in addition to the EPDM rubber.

The invention can also be applied to the manufacture of door weatherstrips that are mounted along the door frame of a motor vehicle door.

As shown in FIG. 2, the door weather strip 2 is attached to a mounting base 21 fitted to a retainer 41 provided along the outer peripheral end surface of the door frame 4 and pressed against a door opening edge of the vehicle body when the door is closed. And a hollow sealing portion 22 to be provided. In the door weather strip 2, the extruded weather strips 2A and 2B are connected in series via a corner-shaped molding connection portion 2C. The horizontal portion of the extruded weather strip 2A and the molded connecting portion 2C connected thereto, that is, the portion to which the upper side portion of the door frame 4 is attached, further extends from the mounting base 21, and the tip is closed when the door is closed. A sub-seal portion 23 is pressed against a portion of the door opening edge along the roof side. The extruded weather strips 2A and 2B are made of EPDM sponge rubber.

Each of the weather strips 2A and 2B is extruded in a sectional shape shown in the drawing. The extruded weather strips 2A and 2B subsequently pass through a vulcanization tank, and are foamed and vulcanized by a foaming agent compounded in rubber. Finally, it is cut to a predetermined length.

Next, the extruded weather strips 2A, 2A
B is formed and connected by a mold. Molded connection 2C
The horizontal part is an extruded weather strip 2A,
The vertical portion has substantially the same cross-sectional shape as the extruded weather strip 2B.

On the molding surface of the cavity of the mold to be used, weather strips 2A and 2 of extruded sponge rubber are provided.
The same fine sponge-like unevenness pattern as the unevenness of the surface of B was formed. The ends of the weather strips 2A and 2B are opposed to each other, set at both ends of a corner-bent cavity, and the cavity is injected and filled with an olefin-based thermoplastic elastomer composed of the same components as those of the opening weather strip described above. . Thus extrusion of the weather strip 2A, 2B is the same sponge skin-like uneven pattern S ₂ and its surface is connected by the molded connecting part 2C which is transferred.

As in the case of the above-described opening weather strip 1, the mold connecting portion 2C of the obtained door weather strip 2 has a release agent that changes the color tone of the surface, and the extrusion weather strip 2A, It does not inhibit the binding to 2B.

[0028]

The weather strip obtained by the present invention has the same concavo-convex pattern continuously formed on the surface of the extruded portion and the molded connection portion, and has a sense of unity over the entire length and has a good appearance. Also, since the mold release agent is not applied to the mold when forming the mold connection part, no clogging occurs on the uneven surface of the mold, and the same mold can be used for a long time, and High productivity because no mold removal operation is required.

[Brief description of the drawings]

1 (A) is a perspective view of a main part of a weather strip manufactured according to the present invention, and FIG. 1 (B) is a view B of FIG. 1 (A);
FIG. 4 is a cross-sectional view taken along line B.

FIG. 2 is a perspective view of a main part of another weather strip manufactured according to the present invention.

[Explanation of symbols]

1,2 weather strip 1A, 1B, 2A, 2B extruded section 1C, 2C molded connecting portions 11, 21 mounting base 12, 22 seal portion 3 vehicle door opening edge flange 4 doorframe S ₁ grain pattern (uneven pattern ) S ₂ uneven pattern

Claims (3)

[Claims] 1. A method of manufacturing a weather strip for an automobile, wherein a terminal of an extruded weather strip is connected in series by molding, wherein the extruded weather strip is made of rubber having a fine uneven surface. With the terminals facing each other, the molding surface is set in a cavity of a mold having the same irregular surface as the above-mentioned irregular surface, and an olefin-based thermoplastic elastomer mixed with a release agent is injected into the cavity, and the extrusion molding wafer is formed. A method for manufacturing a weather strip for an automobile, wherein the strip is formed and connected. 2. The end of an extruded weatherstrip made of rubber having an uneven grain pattern formed on the surface thereof is opposed to a mold cavity formed on the molding surface in the same grain pattern as the grain pattern. 2. The automotive weather strip according to claim 1, wherein the olefin thermoplastic elastomer mixed with a release agent is injected into the cavity, and an extruded weather strip having a textured surface formed on the surface is molded and connected. Manufacturing method. 3. A mold in which the ends of an extruded weather strip made of sponge rubber having a fine irregular surface are opposed to each other, and the molding surface is formed on the same fine irregular surface as the surface of the sponge rubber. 2. The automotive weather according to claim 1, wherein the olefin thermoplastic elastomer mixed with a release agent is injected into the cavity, and a weather strip made of extruded sponge rubber is molded and connected to the cavity. Strip manufacturing method.