JPH0688263B2 - Method for forming corners of weather strip - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for forming a weather strip, particularly a corner portion of a weather strip installed in an opening frame of an automobile door, window, or the like.

[Prior Art] Conventionally, an extruded rubber or plastic strip composed of a main body part having a hollow cross section and a hollow fin part connected to the main body part is cut in its width direction, The cut strips are clamped in a mold for injection molding the corners of the weather strip, rubber or plastic is injected into the concave part of the mold, and the corners are injection-molded at the same time. The corner portion of the weather strip is molded by joining the injection molding portion and the injection molding portion.

When forming the corner and joining the strip to the injection-molded part, insert the hollow core and its core into the concave part of the corner mold that connects to the hollow fin of the strip. It is necessary to provide a core holding member in the mold for holding it stably.

[Problems to be Solved by the Invention] The following problems exist in the conventional method of forming the corners of a weather strip.

I. As described above, since it is necessary to provide the hollow core and the core holding member for molding the hollow fin portion of the corner in the mold, the mold becomes complicated, and therefore the strip is attached to the mold. , It becomes extremely difficult to release the core after molding and joining.

B. The fins formed by injection molding are inferior in surface texture, roughness, luster, and color tone to the extruded fins, and conventional techniques cannot meet the increasingly demanding customer requirements.

[Means for Solving Problems] A method for forming a corner portion of a weather strip according to the present invention for solving the above problems is a main body portion 2a having a hollow cross section and a main body portion 2a. The extruded rubber or plastic strip 2 end composed of the connected hollow fin portion 2b is clamped by a die for injection molding the corners of the weather strip, and the die Injecting rubber or plastic to injection-mold the corner portion 4, and at the same time joining the strip 2 and the corner portion 4, a hollow main body portion on the side of the strip 2 that joins the corner portion 4 By cutting a part 2a 'of 2a, the shape of the strip 2 is such that the hollow fin portion 2b projects from the injection molding portion side.

[Operation] According to the present invention, since the hollow fin portion is formed in the mold, the female die, the core, and the core holding member are not required, and the corner hollow fin portion is integrated with the strip. It is an extruded product with the same roughness, gloss and color tone.

Embodiments Embodiments of the present invention will be described with reference to the drawings. In forming the corners of the weather strip 1, first, as shown in FIG. 1, a main body portion 2a having a hollow cross section and the main body portion 2a.
The end shape of the extruded rubber or plastic strip 2 composed of the hollow fin portion 2b connected to the end is cut off by cutting off a part 2a 'of the body portion 2a at the end. The part 2b is made to project with respect to the main body part 2a (the part shown by the broken line shows a cutout part).

Then, as shown in FIG. 2, the fin portion of the strip 2 of this shape
Pass the core 3 through the hollow portion of 2b.

The strip 2 which has passed through the core 3 is clamped in a mold (not shown) for injection molding of the corners of the weather strip, and rubber or plastic is injected to mold the strip 2.
FIG. 3 shows the joint between the injection molding part 4 and the injection molding part 4 (2
The dotted chain line is the joining line 5.)

[Effects of the Invention] The following effects are exhibited by the practice of the present invention.

I. Since the concave part of the hollow fin part 2b of the mold, the core 3 and the core holding member are omitted, the structure of the mold is simplified, and the strip 2 is attached to the mold and separated after molding. The mold becomes remarkably easy, and the manufacturing cost of the mold and the number of molding steps are reduced.

B. The hollow fins are all extruded parts, and the surface roughness, gloss, and color tone are uniform, and the appearance and quality are improved.
We can meet customers' demands.

[Brief description of drawings]

FIG. 1 is a perspective view of a strip used in the present invention, and FIG. 2 is a perspective view showing a state where a core is inserted into the hollow fin portion of the strip.
FIG. 3 is a perspective view of a weather strip corner portion molded and joined according to the present invention. 1 …… Weather strip 2 …… Extrusion molding strip 2a …… Main body part 2a ′ …… Released part 2b …… Fin part 3 …… Core core 4 …… Injection molding part 5 …… Joining line 6 …… Extrusion Molded part

Claims (1)

[Claims] 1. An extruded rubber or plastic strip (comprising a body portion (2a) having a hollow cross section and a hollow fin portion (2b) connected to the body portion (2a). 2) The ends are clamped in a mold for injection molding the corners of the weather strip, and rubber or plastic is injected into the mold to mold the corners and at the same time as the strip (2). A method for forming a corner portion of a weather strip for joining an injection-molded portion (4), comprising: a part (2a) of a hollow main body portion (2a) on a side of the strip (2) to be joined with the injection-molded portion. By excising ′),
A method for forming a corner portion of a weather strip, characterized in that the shape of the strip (2) is such that a hollow fin portion (2b) is projected from the injection molding portion side.