JP3300250B2 - Welt and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a long welt having a substantially U-shaped cross section in which a core material is covered with rubber or a synthetic resin material, and a method for producing the same.

[0002]

2. Description of the Related Art For example, a belt-shaped metal core material covered with rubber or synthetic resin material is fitted with a welt having a substantially U-shaped cross section on a flange portion such as a panel fitting portion or an edge portion of an automobile. I have. In the production of such a welt,
First, an intermediate molded body obtained by simultaneously extruding a core material and a rubber or synthetic resin material is bent into a U-shape after vulcanization or cooling. Thereafter, the molded part is integrally molded with the end of the extruded part obtained by cutting to a predetermined length, if necessary.
Connected. Conventionally, the welt manufactured in this manner has a problem that unevenness in which the core material is embossed is formed on the surface of the coating portion of the extruded portion for coating the core material, and the appearance quality is impaired.

To cope with such a problem, for example, in Japanese Utility Model Laid-Open Publication No. Sho 62-16543, a film-like skin is integrally formed with a hollow portion interposed on the outer surface of a covering portion for covering a core material. The skin is configured to cover the outer surface of the covering portion where the uneven portion is formed. Further, in the method disclosed in Japanese Utility Model Laid-Open Publication No. 3-22954, when extruding an intermediate molded body, a sub-lip is formed on a coating portion covering a core material, and the sub-lip is pressed on the surface of the coating portion immediately after extrusion. The sub lip is configured to cover the uneven portion generated on the surface of the covering portion.

[0004]

Problems to be Solved by the Invention
In the method disclosed in Japanese Patent Publication No. 3 (2003), when molding the molded part at the end of the extruded part having the hollow part, the material is prevented from flowing into the hollow part at the end of the extruded part in order to prevent the dough from flowing into the hollow part. It is necessary to insert a core mold or to crush the hollow part with a mold. When a core mold is used, the core mold must be extracted from the product after the completion of the molding, which complicates the production and requires a hole for core removal on the outer surface of the welt. , Appearance quality deteriorates. On the other hand, when the hollow portion is crushed during the molding, there is a problem that a scar or a step is formed on the outer surface of the extruded portion after the molding, and the appearance quality of the product is impaired. Further, such a film-like skin is likely to bend in a wavy shape due to pressure fluctuations during extrusion molding and the like, and the appearance quality of the product may be impaired.

On the other hand, in Japanese Utility Model Laid-Open Publication No. 3-22954, the sub-lip and the coating portion are integrated with each other because the sub-lip is press-bonded to the surface of the coating portion in a soft state before cooling. May be exposed on the surface of the sub lip. However, it is difficult to press-bond the sub lip after the cold molding, and there is a problem that the sub lip is easily peeled.

[0006]

SUMMARY OF THE INVENTION Accordingly, the invention of claim 1 is to provide an intermediate molded body obtained by extruding a core material and a rubber material or a synthetic resin material, after vulcanizing or cooling, and then having a substantially U-shaped section. A welt formed by bending an extruded part by bending into a letter shape, wherein the intermediate molded body is a thin film formed integrally with a covering part covering the core material and a hollow part interposed on the outer surface of the covering part. And wherein in the step of bending the intermediate molded body, the skin layer is stretched and substantially abuts the outer surface of the covering portion.

A second aspect of the present invention is a welt in which a molded part made of rubber or synthetic resin is integrally connected to a terminal of the extruded part, and the intermediate molded body is bent. The hollow portion is substantially closed.

[0008] The invention of claim 3 includes an extrusion step of extruding a core material and a rubber or synthetic resin material to obtain an intermediate molded body, a step of vulcanizing or cooling the intermediate molded body, A bending step of bending into a U-shape, and a terminal of a long extruded part obtained by cutting the intermediate molded body to a predetermined length,
A step of integrally molding and connecting a molded part made of rubber or synthetic resin, wherein the intermediate molded body has a covering part covering the core material, and a hollow part interposed on the outer surface of the covering part. And a thin skin layer integrally formed with the coating layer. In the bending step, the skin layer is stretched and substantially abuts the covering portion, and the hollow portion is substantially closed. It is characterized by:

The above-mentioned molded portion constitutes, for example, a welt end portion, or in the case of a welt attached to a bent corner portion, the terminals of two different extruded portions are connected to each other. This constitutes a formed corner portion. In the case of a closed annular welt, the molded part is molded so as to connect the terminals of one extruded part.

[0010]

According to the first and third aspects of the present invention, the irregularities due to the protrusion of the core material formed on the outer surface of the covering portion of the intermediate molded body immediately after extrusion are covered by the skin layer and exposed to the outside. As a result, the appearance quality of the welt as a product is significantly improved.

Here, when the skin layer is in a soft state immediately after extrusion molding, it is separated from the outer surface of the covering portion via the hollow portion, and substantially contacts the outer surface of the covering portion in the bending step after vulcanization or cooling. Because of the contact, there is no possibility of being integrated with the covering portion, and therefore, the uneven portion formed on the outer surface of the covering portion does not affect the outer surface of the skin layer.

Further, since the skin layer is formed into a thin film via a hollow portion, the skin layer may bend in a stage from the extrusion step to the vulcanization or cooling step. Is stretched and smoothed. Therefore, the surface of the weld after molding is smooth and has a good appearance.

Furthermore, as in the second and third aspects of the present invention, when forming the molded part at the end of the extruded part, the hollow part of the extruded part is already substantially closed in the bending step. ,
There is no need to insert a core mold into the hollow portion in advance or to crush the hollow portion during molding as in the conventional example. Therefore, the production is facilitated, and there is no hole, a scar or a step for removing the core die on the surface of the weld, and the appearance is excellent.

[0014]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below.

FIGS. 1 and 2 show a welt 10 according to a first embodiment of the present invention. The welt 10 has a configuration in which a molding part 12 as a welt terminal is integrally molded and connected to a terminal 11a of a long extrusion part 11 having a substantially U-shaped cross section. The extruded portion 11 has a core material 13 made of a band-shaped metal and a coating portion 14 made of a synthetic resin that covers the core material 13.
It is formed in a channel shape having a base 1b and a base 11c. A total of four flange retaining lips 15 are integrally formed on the inner surface of the channel, and a hollow portion 16a, which is closed in a later-described bending process during manufacturing, is formed on the outer surface of the covering portion 14 on the outer side of the channel. The skin layer 17 in the form of a thin film is integrally formed with the interposition therebetween.

Next, a method of manufacturing the welt 10 will be described in the order of the steps shown in FIG. First, in step S1, primary bending is performed by using a pre-bender or the like to bend the flat core material 13 into a substantially rectangular shape as shown in FIG. In the following step S2, the primary bent core material 13
And the synthetic resin material are simultaneously extruded from the base not shown,
As shown in FIG. 3, the intermediate molded body 18 in which the core material 13 is embedded in the covering portion 14 is continuously extruded. Here, the covering portion 14 has a flange holding lip 15
And a thin skin layer 17 is integrally formed on the outer surface side with a flat hollow portion 16 interposed therebetween.

After being cooled in step S3, the intermediate molded body 18 is subjected to secondary bending using a bender or the like in step S4, and is bent into an accurate substantially U-shaped cross section.
In the subsequent step S5, the extruded portion 11 is cut into an appropriate length, and a long extruded portion 11 having a substantially U-shaped cross section as shown in FIG. 1 is continuously formed.

Here, since the skin layer 17 extends in the width direction over the area of the corner portion bent to the base portion 11c and the side wall portion 11b, it is elongated in the width direction in the bending step of step S4. It is elastically deformed to shift inward. As a result, the skin layer 17 and the outer surface of the covering portion 14 substantially abut and adhere to each other, and the hollow portion 16 is substantially closed or eliminated (see FIGS. 1 and 2).

Thereafter, in step S6, the molding part 12 is molded at the terminal 11a of the extrusion molding part 11 by a known molding method, and the welt 10 as shown in FIGS. . That is, the resin material is supplied into the mold cavity in a state where the terminal portion of the extrusion molding unit 11 is set in the mold, and the mold molding unit 1 is subjected to an appropriate process such as cooling.
2 is formed and connected to the terminal 11a of the extrusion forming section 11.

The welt 10 thus manufactured
Since the uneven portion 19 (FIG. 3) formed by the protrusion of the core material 13 formed on the outer surface of the covering portion 14 is covered and concealed by the smooth skin layer 17, the surface of the welt 10 is smoothed and its appearance quality is improved. Is significantly improved. In addition, the skin layer 17
Are formed in a region where appearance quality is required. In this embodiment, the base 11c of the extruded portion 11 and the side walls 1 are formed.
1b is formed over the corner portion bent.

Here, when the skin layer 17 is in a soft state immediately after extrusion molding in step S2, it is separated from the outer surface of the covering portion 14 via the hollow portion 16, and the bending in step S4 following the cooling in step S3. Covering part 14 in the process
Since it is in contact with the outer surface, the outer surface of the skin layer 17 is not affected by the uneven portion 19 formed on the outer surface of the coating portion 14 because the outer surface of the skin portion 17 is not integrated with the coating portion 14.

Further, in the course of proceeding from the extrusion step of step S2 to the cooling step of step S3, the skin layer 17 may bend into a wavy shape due to a pressure fluctuation in the hollow portion 16 or the like. In the example, since the skin layer 17 is elongated in the bending step of step S4, the skin layer 1 in the final product is formed.
7 is smooth without bending.

Further, if a hollow portion is opened at the end 11a of the extruded portion at the time of molding in step S6, a core mold is inserted in advance into the hollow portion in order to prevent the dough from flowing into the hollow portion. Or it is necessary to crush the hollow portion with a mold, which makes the production complicated and scars when the hole for hollow core or the hollow portion is crushed on the surface of the extruded portion 11 after molding. , Steps remain, and the appearance quality is degraded. However, in the present embodiment, since the hollow portion 16 of the extruded portion 11 is substantially closed in the bending process in step S4, the molding process in step S6 is the same as the process without the hollow portion 16 from the beginning. Can be molded. As a result, the production becomes extremely easy, and the surface of the extruded portion 11 after molding becomes smooth without holes, scars, and steps for removing the core.

FIG. 5 shows an extruded portion 21 of the welt 20 according to the second embodiment of the present invention, and FIG.
It is a cross-sectional view showing the intermediate molded body 28 of FIG. In the second, third, and fourth embodiments described below, portions corresponding to the configurations described in the first embodiment described above are 10, 2 and 4, respectively.
The reference numerals obtained by adding 0 and 30 are assigned, and the description of the overlapping configuration and the function and effect is omitted as appropriate.

In the welt 20 of the second embodiment, the skin layer 27 is formed wider than the welt 10 of the first embodiment, and more specifically, the skin layer 27 and the hollow portion 26 are formed of a core material 23. Extend in the width direction over the entire region where the exists. For this reason, in the formed welt 20, the smooth skin layer 27 extends from the base 21 c of the extruded part 21 to both side walls 21 b so as to surround the outside of the core 23, and the surface of the covering part 24 Since the uneven portion 29 formed on the wedge 20 is covered, the entire surface of the welt 20 is smoothed, and the appearance quality is significantly improved.

This welt 20 is used in step S2 of FIG.
It is manufactured through the same steps as in S6. That is, in the second embodiment, the core material primary bending step in step S1 is omitted, and first, in step S2, a flat intermediate molded body 28 is extruded. After being cooled in step S3, the intermediate molded body 28 is bent into a substantially U-shaped cross section in the bending step in step S4. In this bending step, the skin layer 27 substantially adheres to the surface of the covering portion 24 on which the uneven portions 29 are formed, and the hollow portion 26 is closed.

In the second embodiment, the same effect as that of the first embodiment can be obtained, and in addition, the flat intermediate body 28 is bent at a step S4 into a substantially U-shaped cross section. , Its skin layer 27 is greatly stretched,
The hollow portion 26 is more reliably closed.

FIG. 7 shows a third embodiment of the present invention, in which a welt 30a according to the present embodiment is used as a mounting base for a weather strip 30 having a hollow sealing lip 30b. That is, the weather strip 30
The hollow seal lip 30b is formed on one of the side walls 31b of the welt 30a facing each other.

The method of manufacturing the weather strip 30 will be described with reference to FIG. 4. In step S1, the core 33 is bent into a dogleg shape, and the core 33 and the covering portion 34 of the welt 30a are formed. A solid rubber material for forming the skin layer 37 and a sponge rubber material for forming the hollow seal lip 30b are simultaneously extruded, and an intermediate portion in which the hollow seal lip 30b is formed on the outer surface of the covering portion 34 covering the core material 33. The molded body 38 is molded. This intermediate molded body 38
Is vulcanized in the following step S3, then bent into an accurate shape in a step S4, and cut into an appropriate length in a step S5, so that a substantially U-shaped cross section with a hollow seal lip 30b is provided. A long extruded part 31 is continuously formed. In step S6, a molded part (not shown) made of solid rubber is integrally connected to the end of the extruded part 31.

FIG. 8 shows a weather strip 40 having a welt 40a according to a fourth embodiment of the present invention. In this fourth embodiment, a third embodiment is similar to the second embodiment of the first embodiment. The skin layer 47 is formed wider than in the example, and specifically, extends in the width direction over the entire region where the core material 43 exists. For this reason, in the formed welt 40, the uneven portion 49 formed on the surface of the covering portion 44 is covered by the smooth skin layer 47 extending so as to surround the outside of the core material 43. The entire surface of 40a is smoothed, and its appearance quality is significantly improved.

As described above, the effects of the third and fourth embodiments, which are used for the mounting base of the weather strip, are similar to those of the first and second embodiments. Can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view corresponding to a welt according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the weld of FIG. 1 cut in a longitudinal direction.

FIG. 3 is a cross-sectional view of an intermediate molded body formed at the time of manufacturing the welt of FIG. 1;

FIG. 4 is a manufacturing process diagram of the welt of FIG. 1;

FIG. 5 is a sectional perspective view of a welt according to a second embodiment of the present invention.

FIG. 6 is a cross-sectional view of an intermediate molded body formed at the time of manufacturing the welt of FIG. 5;

FIG. 7 is a cross-sectional perspective view of a weather strip provided with a welt according to a third embodiment of the present invention.

FIG. 8 is a cross-sectional perspective view of a weather strip including a welt according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Welt 11 ... Extruded part 11a ... Terminal 12 ... Mold forming part 13 ... Core material 14 ... Coating part 16, 16a ... Hollow part 17 ... Skin layer 18 ... Intermediate molded body 19 ... Uneven part

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B29D 31/00 B29D 69/00-69/02 B29C 47/00-47/96 B60R 13/02-13 / 06

Claims (3)

(57) [Claims] An intermediate molded body obtained by extruding a core material and a rubber material or a synthetic resin material is vulcanized or cooled, and then bent into a substantially U-shaped cross-section to form an extruded portion. The intermediate molded body has a covering portion for covering the core material, and a thin skin layer integrally formed with a hollow portion interposed on the outer surface of the covering portion, and the intermediate molded body is A welt characterized in that, in the bending step, the skin layer is stretched to substantially contact the outer surface of the covering portion. 2. A welt in which a molded part made of rubber or synthetic resin is integrally connected to a terminal of the extruded part, wherein the hollow part is substantially formed in a step of bending the intermediate molded body. The welt according to claim 1, wherein the welt is closed. 3. An extrusion step of extruding a core material and a rubber or synthetic resin material to obtain an intermediate molded body, a step of vulcanizing or cooling the intermediate molded body, and bending the intermediate molded body into a substantially U-shaped cross section. A bending step, and a step of integrally molding and connecting a molded part made of rubber or synthetic resin to a terminal of a long extruded part obtained by cutting the intermediate molded body into a predetermined length. The intermediate molded body has a covering portion covering the core material, and a thin skin layer integrally formed by interposing a hollow portion on the outer surface of the covering portion, A method for producing a welt, wherein the skin layer is stretched and substantially abuts the covering portion, and the hollow portion is substantially closed.