JP3066695B2 - Automotive weather strip - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weather strip for automobiles in which a molded part is integrally formed with an extruded part by heat bonding.

[0002]

2. Description of the Related Art Conventionally, weather strips for automobiles are:
Generally, the extruded part is formed by integrally heat-molding the molded part. Both the extruded part and the molded part are made of a rubber composition containing EPDM as a main component. Various types of hard rubber, sponge rubber alone, a composite of the two, a composite of hard rubber and metal, a composite of the three, and the like are used.

FIGS. 1 and 3 each show a conventional example, in which 10 is an extruded portion, 20 is a molded portion integrally formed with the extruded portion 10 by heat bonding, and FIGS.
3 is a sectional view of the extruded portion 10 shown in FIGS. 1 and 3, wherein 11 is a hard rubber portion, 12 is a sponge rubber portion, and 13 is a flocked or painted portion.

[0004] However, all of the above conventional automotive weather strips require vulcanization treatment, and therefore, the molded parts which require strict vulcanization conditions, particularly at 160 to 200 ° C for 2 to 20 minutes. As for molding, the molding cycle becomes longer, a large amount of mold and press and its processing space are required, and moreover, many burrs are generated between the mating surfaces of the molds that are distorted by being exposed to high temperatures, and the removal of the burrs is considerable. Is troublesome, which raises the cost.

[0005]

The problem to be solved is that the conventional weatherstrip described above requires a long molding cycle of a molding section, requires a large amount of molds and presses, and a large working space thereof. The cost is increased due to the removal of a large amount of burrs generated between the mating surfaces of the mold distorted by high temperature.

[0006]

A description will be given with reference to FIGS. In the present invention, the extrusion molding section 30 is provided with a molding section 40.
Is a heat-sealable automobile strip formed integrally with the above, and the hard rubber equivalent part 31 of the connection section 30 of the extruded part is slightly foamed with a foaming ratio of 1 to 10%, and the appearance and performance of the hard rubber are approximated. The molded part 40 is made of a pseudo-hard rubber and the molded part 40 is made of a thermoplastic resin.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described. An extruded portion 30 of a weatherstrip is shown in FIG. 5 and FIG. is there.

FIGS. 7 and 8 show a composite of a hard rubber equivalent portion 31 and a sponge rubber portion 32. In each case, the hard rubber equivalent portion 31 is slightly foamed with a foaming ratio of 1 to 10%. And a molded part 40 connected to the extruded part 30 is made of a thermoplastic resin.

To explain the operation, the foaming rate of the extruded part was changed and the physical properties and the adhesive strength between the extruded part and the molded part were examined. The results shown in Table 1 were obtained.

[0010]

[Table 1] Influence of foaming rate of extruded part

* Foaming rate = [(kneading specific gravity / product (vulcanized product) specific gravity) -1] * 100 (%)

The resin used in the molded part is Sumitomo TPE2.
22 D-2 (polyolefin type) was used.

As is clear from Table 1, if the foaming rate of the extruded portion 30 is increased, the adhesive force of the molded portion 40 with the resin is not so reduced, but the physical properties are reduced and the appearance is reduced to sponge rubber. Therefore, the foaming ratio of the extruded part 30 is 1
10% to 10% is preferable. That is, the present invention in which the hard rubber equivalent portion 31 of the extruded portion 30 is made of pseudo hard rubber slightly foamed with a foaming ratio of 1 to 10% and the molded portion 40 is made of a thermoplastic resin, Due to the foaming, the contact area of the connection cross section increases, the bonding strength at the time of joining increases, the various obstacles seen in the above conventional example are eliminated, the molding time is shortened, and the cost is greatly reduced.

[0014]

Since the present invention is configured as described above,
Heat bonding between the extruded part 30 and the molded part 40 is facilitated, the productivity is improved, and the cost is greatly reduced. Previously, it was attempted to form the molded part with a thermoplastic resin, but the adhesive strength with the hard rubber part of the extruded part was weak, and even if it was supplemented by primer treatment etc., until sufficient adhesive strength was obtained And has not been put to practical use.

[Brief description of the drawings]

FIG. 1 is a front view showing a conventional example.

FIG. 2 is a cross-sectional view of the extruded part of FIG.

FIG. 3 is a front view showing another conventional example.

FIG. 4 is a cross-sectional view of the extruded part of FIG.

FIG. 5 is a front view showing the first embodiment of the present invention.

FIG. 6 is a cross-sectional view of the extruded part of FIG.

FIG. 7 is a front view showing a second embodiment of the present invention.

FIG. 8 is a cross-sectional view of the extruded part of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Extruded part 11 Hard rubber part 12 Sponge rubber part 13 Flocked or painted part 20 Mold part 30 Extruded part 31 Hard rubber equivalent part 32 Sponge rubber part 33 Flocked or painted 40 Mold part

Claims (1)

(57) [Claims] 1. A molding part (40) in an extrusion molding part (30 ).
In automobile weather strip heated joined integrally molded, hard rubber corresponding portion of the extruded portion connecting section (3
1) is an automotive weather strip which is slightly foamed with a foaming ratio of 1 to 10%, is made of pseudo-hard rubber similar in appearance and performance to hard rubber, and whose molded part is made of a thermoplastic resin.