JPH0242345B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a weather strip that is attached to an opening in an automobile body or around an opening/closing member such as a door or trunk lid that opens and closes the opening.

[Prior Art] As shown in FIG. 7C, this type of weather strip includes a base portion 11 having a U-shaped cross section, a seal portion 12a protruding from the outer surface of the base portion 11, and an auxiliary seal portion 12b as necessary. .

The base 11 of the weather strip 1' is made of solid rubber, and has a retaining lip 13 on the inner surface for holding a flange of an automobile body opening, etc.
A sheet metal core material 14 is embedded in the character member. The seal parts 12a and 12b are made of sponge rubber.

6 and 7 show the conventional manufacturing process of a weather strip in which the core material 14' is embedded.

The core material 14' is, for example, formed by forming slots at predetermined intervals in the length direction in the widthwise center of a long flat sheet metal, and forming slits from both ends of every other slot to the side edges of the sheet metal. is used. When this sheet metal is subjected to vertical bending stress on its surface, the stress concentrates on the slit 142 and breaks there, resulting in a large number of core pieces.

First, the sheet metal core material 14' is sent out from the truck 2.
This core material 14' is integrally extruded with solid rubber and sponge rubber by an extruder 3. FIG. 7B shows a cross section of the extruded product, in which the core material 14' is wrapped in solid rubber, the retaining lip 13 protrudes from the bottom surface of the solid rubber, and both seal parts 12a and 12b of sponge rubber protrude from the top surface. There is.

Next, the extruded body is sent to a high frequency induction heating device 4 and further to a high frequency dielectric heating device 5. In the high frequency induction heating device 4, the metal core material 14' is 120~
The rubber material is heated to 150°C, and the rubber material is heated to about 200-220°C by high-frequency dielectric heating. The extruded body is then passed through a hot air tank 6 and maintained at around 200°C to be vulcanized, taken off by a take-off machine 7, and then cooled in a cooling tank 8.

The cooled extrudate is then sent to a core separator 9. In the separator 9, a roller repeatedly applies bending stress to the extruded molded product in a direction perpendicular to the core material surface, and the core material 14' in the molded product is broken at the slit 142, which is a stress concentration area, and the core material 14' is divided into many pieces of core material.

Next, the extrusion molded product is sent to a U-shaped bending machine 10, where the solid rubber part surrounding the core material 14' is bent into a U-shaped cross section to form the base part 11, as shown in FIG. 7C. product is obtained. The product is finally cut into a predetermined length by a cutting machine 10.
It is cut at 0.

In order to manufacture a weather strip having a core material as described above, a long process is required, and there is a need to simplify the manufacturing method. In particular, in the core material separation process using a core material separator, the number of stations is approximately 15 and bending stress is applied repeatedly, and the core material is
A large load of about 4 kg/cm ² is required to bend it into a shape.

Under these circumstances, there is a strong demand for simplifying the separation of the core material and the bending process during the manufacturing process.

[Problems to be Solved by the Present Invention] In view of the above-mentioned circumstances, the present invention provides a weather strip in which a divided core material is embedded, by simplifying the manufacturing process, especially the separation and bending process of the core material. Make manufacturing easier,
The aim is to solve the problems of the conventional technology.

[Means for Solving the Problems and Effects] As a result of various studies to achieve the above object, the inventors found that thermoplastic resins such as vinyl chloride resin and ABS resin were used as the core material for weather strips. We focused on using a core material made of resin.

Therefore, the present invention uses a core material of thermoplastic synthetic resin, and the first manufacturing method includes, after vulcanization,
It is characterized in that the core material is broken by cooling, then the extrusion molded body is preheated to soften the core material to perform U-shaped bending, and the U-shape of the core material is maintained by cooling.

In this method, since the core material is made of synthetic resin, it can be easily broken with fewer stations than a metal core material. Furthermore, in U-shaped bending, the bending process is performed on a synthetic resin core material that has been preheated and softened, so that the process can be easily performed with a small load.

In the second manufacturing method of the present invention, after vulcanization, the extruded body in which the core material is in a softened state is preformed with a small bending angle that does not result in a U-shape, and then the core material is brought into a semi-hardened state. The feature is that the core material is slowly cooled until the core material is broken, and then U-shaped bending is performed immediately after the core material is broken.

The difference from the first manufacturing method is that during the cooling process of the extruded product after vulcanization, the core material is preformed in a softened state, and the core material is broken and U-shaped bent in a semi-hardened state. be. U-shaped bending can be easily performed even in a semi-cured state since the core material has already been preformed.

In the present invention, in the vulcanization step, it is also possible to use a conventional method of raising the temperature of the extruded body from the outside using a heating medium such as glass beads.

However, high frequency dielectric heating is preferably used.
In this case, there is no need to use high-frequency induction heating in conjunction with the conventional method. In other words, in the case of a metal core material, the temperature of the core material is first raised by high-frequency induction heating, and then the temperature of the rubber material is raised by high-frequency dielectric heating, but with a synthetic resin core material, the temperature of the core material is raised together with the rubber by high-frequency dielectric heating alone. The temperature of the rubber material can also be raised to sufficiently vulcanize the rubber material.

In addition, in the vulcanization process, the softened synthetic resin core material cannot be pulled out from the end of the process due to its strength. Therefore, it is necessary to provide a conveying means such as a belt conveyor in part or all of the vulcanization process to reduce the tension applied to the extruded product as much as possible.

[Example] In the present invention, the core material is a thermoplastic synthetic resin,
For example, a core material of ABS resin or vinyl chloride resin is used. The shape is the same as the conventional one, for example, as shown in FIG. 3, slots 141 in the width direction are formed in a long flat plate at predetermined intervals in the longitudinal direction.
Slits 142 are formed between both ends of every other slot and both side edges of the flat plate. The slit 142 forms a stress concentration area where stress is concentrated when bending stress is applied to the core material 14.

1 and 2 show a first manufacturing method of the present invention, which will be explained in comparison with the conventional method shown in FIGS. 6 and 7 above.

First, in the core material feeding step, the flat core material 14 is fed from the cart 2. Next, in the extrusion molding process,
The core material 14 is integrally extruded with the rubber material by the extruder 3. Figure 2B shows an extruded product.
The core material 14 is wrapped in solid rubber, and seal parts 12a and 12b made of sponge rubber protrude from the solid rubber.

The extrudate is then sent to a vulcanization process. That is,
The extrusion molded product is heated to 120 to 150℃ using the high frequency dielectric heating device 5.
The material is heated to a certain temperature, and is vulcanized during a heat retention process in which it passes through a hot air tank 6 at 200 to 220°C. The present invention does not require the induction heating device 4 (FIG. 6).

Next, the extruded body is cooled in a cooling tank 8 and taken off by a take-off machine 7, and then undergoes a core material separation step. That is, in the separator 9, the extruded molded product has the core material 1 embedded therein.
A vertical bending stress is applied to the surface of core material 1.
4 is broken at the slit 142 (FIG. 3) in the stress concentration area. At this time, the resin core material is easier to break than the metal core material, and the number of roller stations can be reduced.

Next, the extruded product undergoes a preheating process in a preheating tank 6A.
The core material 14 is heated to about 120° C. and softened, leading to the base forming process, as shown in FIG. 2C.
The base portion in which 4 is embedded is bent into a U-shaped cross section by a bending machine 10. The resin core material 14 heated to around 120° C. in the preheating tank 10A can be bent into a U shape with much smaller stress than a metal core material.

The obtained product is immediately cooled by a cold air blower 8A to maintain the U-shape of the core material 14, and then cut to a predetermined length by a cutter 11.

4 and 5 show the second manufacturing method of the present invention, which is the same as the first manufacturing method until the extruded body is vulcanized through the hot air tank 6.

Immediately after vulcanization, the extruded product is preformed using a bending machine 10A. At this time, the core material 14 is softened, and the solid rubber portion including the core material 14 is bent at a small bending angle that does not result in a U-shape, as shown in FIG. 5B.

The preformed extrusion molded body is then passed through a slow cooling tank 8B.
where it is slowly cooled to about 120 to 100 degrees Celsius.
The core material 14 is in a semi-hardened state. In this state, the core material 14 is broken by the core material separator 9, and immediately bent into a U-shape by the bending machine 10. The core material 14 can be broken in a semi-hardened state, and since it is preformed, it can also be bent into a U-shape.

Immediately after the bending process, the weather strip 1 is stabilized into a U-shape by being cooled by the cold air supply device 8A, and the weather strip 1 as shown in FIG. 4C is obtained.
This weather strip 1 is cut into a predetermined length by a cutting machine 100.

As explained above, in manufacturing the weather strip of the present invention using thermoplastic synthetic resin such as ABS resin or vinyl chloride resin as the core material, the load during bending of the core material can be small, and the manufacturing process can be simplified. Furthermore, the obtained product is extremely advantageous in that it is lighter than those using conventional metal core materials, and there is no problem of corrosion of the core materials.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the manufacturing process of the first manufacturing method of the present invention, and Fig. 2 A, B, and C are respectively A of Fig. 1.
-A line, B-B line, C-C line sectional view, Figure 3A,
B is a plan view and a side view of the core material, FIG. 4 is a diagram showing the manufacturing process of the second manufacturing method of the present invention, FIGS. 5A, B, and C are lines AA in FIG. 4, B-B
line, C-C line cross-sectional view, Figure 6 is a diagram showing the conventional manufacturing process, Figure 7 A, B, and C are respectively A of Figure 6
-A, B-B, and CC line cross-sectional views. 1... Weather strip, 11... Base, 12
a, 12b... Seal part, 14... Synthetic resin core material, 3... Extruder, 4... High frequency induction heating device,
5... High frequency dielectric heating device, 6... Hot air tank, 8...
...Cooling tank, 8A...Cold air feeder, 8B...Learning tank, 9...Core material separator, 10, 10A...Bending machine, 100...Cutting machine.

Claims (1)

[Scope of Claims] 1. A method for manufacturing a weather strip for an automobile, comprising a mounting base having a U-shaped cross section, a seal portion protruding from the mounting base, and a number of divided core materials embedded in the mounting base, the method comprising: a step of feeding a long flat core material made of plastic synthetic resin and having stress concentration parts formed at predetermined intervals in the longitudinal direction; an extrusion molding step of integrally extruding the core material and a rubber material; There is a vulcanization process in which the rubber material is vulcanized by raising and keeping the temperature of the obtained extrusion molded body, a cooling process in which the vulcanized extrusion molded body is cooled, and a core is formed by applying bending stress to the cooled extrusion molded body. a core material separation step in which the material is broken at its stress concentration area; a core material preheating step in which the extrusion molded body containing the divided core material is heated to soften the core material;
An automobile comprising a base forming process in which the core material is bent into a U-shaped cross section together with the rubber containing the core material, a cooling process in which the obtained weatherstrip is cooled, and a cutting process in which the cooled weatherstrip is cut into a predetermined length. Method of manufacturing weather strips for 2. A method for manufacturing an automobile weather strip, which is equipped with a mounting base having a U-shaped cross section, a seal portion protruding from the mounting base, and a number of divided core materials embedded in the mounting base, the weather strip being made of thermoplastic synthetic resin and having a longitudinal length. A step of feeding a long flat core material in which stress concentration parts are formed at predetermined intervals in a direction, an extrusion molding step of integrally extruding the core material and a rubber material, and the obtained extrusion molded product. A vulcanization process in which the rubber material is vulcanized by raising the temperature and keeping it warm, and bending the softened core material of the vulcanized extruded product together with the solid rubber containing it into a cross-sectional shape with a bending angle smaller than the U-shape. There is a preforming process for processing, an annealing process for slowly cooling the preformed extrusion molded body until its core material reaches a semi-hardened state, and a stress is applied to the slowly cooled extrusion molded body to bring it into a semi-hardened state. a core material separation step in which the core material is broken at its stress concentration area; a base forming step in which the preformed and divided core material in a semi-hardened state is bent into a U-shaped cross section together with the rubber containing it; A method for producing a weather strip for an automobile, which comprises a cooling step of cooling the obtained weather strip and a cutting step of cutting the cooled weather strip into a predetermined length.