JPH0376256B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a weather strip that seals between an opening in an automobile body and an opening/closing member that opens and closes the opening.

[Prior Art] As shown in FIG. 11, this type of weather strip has a base 11 that has a U-shaped cross section and has a retaining lip 13 on its internal facing surface that holds a flange of a body opening, and a seal portion 1 that protrudes from the outer surface of the base 11.
2a and, if necessary, a lip-shaped auxiliary seal portion 12b.

The base 11 of this weather strip 1 is made of solid rubber, and a core material 14 of sheet metal is embedded therein. The seal parts 12a and 12b are made of sponge rubber. In order to improve the bending deformability of the weather strip 1, the core material 14 is often divided into a number of core material pieces as shown in FIG. 12. Core material 1
4 is separated in the process of manufacturing the weather strip 1.

The weather strip 1 is manufactured by extrusion molding. FIG. 13 shows the core material 14 before extrusion molding, in which slots 141 in the width direction are formed in a long flat sheet metal at predetermined intervals in the longitudinal direction. The slots 141 alternate in length. When a bending stress is applied to the core material 14 in a direction perpendicular to the surface of the core material, the stress is concentrated on the narrow portions 140 at both ends of the long slot and the core material 14 is broken, resulting in a divided state as shown in FIG.

To manufacture the weather strip 1 shown in FIG. 11, a sheet metal core material 14 as shown in FIG. 13 is supplied, and solid rubber and sponge rubber are integrally extruded to form the core material 14. Wrap it in a flat plate and seal part 1 from this solid rubber.
An extrusion molded body having protruding portions 2a and 12b is obtained.

Next, the extruded body is sent to a high frequency induction heating device, and further sent to a high frequency dielectric heating device. In the high-frequency induction heating device, the metal core material 14 is heated to 120 to 150°C, and the rubber material is heated to 200°C by high-frequency induction heating.
Heated to ~220℃. The extruded body is then passed through a hot air tank, maintained at around 200℃, and vulcanized.
It is cooled in a cooling tank.

The cooled extrudate is then sent to a core separator. In the separator, rollers repeatedly apply 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 stress concentration area, and the core material is broken as shown in FIG. It is divided into many core pieces.

Then the extrudate is sent to a U-bending machine,
The solid rubber part surrounding the core material 14 is bent into a U-shaped cross section to form the base part 11, and a weather strip product is obtained. The product is finally cut to a predetermined length using a cutting machine.

[Problems to be Solved by the Present Invention] By the way, if the core material is divided, the weather strip has good bending deformability and can be easily attached to the corner of the body opening, but on the other hand, inconveniences may also occur. .

That is, when a weather strip is attached to a flange of a body opening, it is attached sequentially in the longitudinal direction with a slight tension applied, but since this is generally done by hand, there is a possibility that the weather strip may sag or become too stretched due to too much or too little tension. There is. Particularly at corner portions as shown in FIG. 12, sagging or excessive elongation is likely to occur, causing the weather strip to fall off.

In addition, in the manufacturing process, the core material separation process using a core material separator uses approximately 15 stations to repeatedly apply bending stress, and in order to bend the core material into a U-shape, a large amount of approximately 4 kg/cm ² is required. Requires pressure.

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

Therefore, the present invention aims to create a lightweight weather strip that has sufficient bending deformability and does not sag or stretch when attached to a corner part, especially a corner part that curves in the width direction of the weather strip, and is simpler than the conventional one. The object of the present invention is to provide a manufacturing method that can be manufactured by the means described above.

[Means and effects for solving the problems] In the method for manufacturing a weather strip of the present invention, a thermoplastic synthetic resin, such as ABC resin,
A core material made of vinyl chloride resin, polypropylene resin, etc. is used. In addition, the core material has a part in the width direction, for example, as shown in Fig. 2, one end that becomes the inner diameter side of the corner part when installed is continuous in the longitudinal direction, and the part that becomes the outer diameter side is formed at a predetermined interval in the longitudinal direction. It has a divided form.

In the first manufacturing method of the present invention for obtaining a weather strip, first, as shown in FIG. A thermoplastic synthetic resin core material 14 divided at predetermined intervals in the longitudinal direction is extruded together with a rubber material to obtain an extruded body as shown in FIG. 5B, and the extruded body is heated and kept warm. After vulcanization, while the core material is in a softened state, U
Bending is performed to obtain a product as shown in Figure 5C, and the product is cooled.

This method does not require breaking the core material. Also,
Since the U-shaped bending is performed while the resin core material is softened after vulcanization, the process can be simplified and the bending process can be easily performed with a small load.

In the second manufacturing method of the present invention, as shown in FIG. 7, the center portion in the width direction is separated by a slot 141 at a predetermined interval in the longitudinal direction, and one end portion forms a continuous portion 142 in the longitudinal direction, The other end uses a core material 14 made of thermoplastic synthetic resin that can be broken along a score line 143. In this method, extrusion molding and vulcanization are performed in the same manner as in the first manufacturing method. Next, the extrusion molded body is cooled and the core material 14 is cut along the score line 143.
After that, the core material is preheated to soften it, and then U-shaped bending is performed.

Note that the difference from the first method is that a core material whose both ends are connected is used, and one of the both ends is broken after extrusion molding. This is to eliminate the possibility that the core material will be deformed during extrusion molding, as will be described later.

In the present invention, in the vulcanization process, it is possible to use a conventional means of raising the temperature of the extruded body from the outside using a heating medium such as glass beads, but it is more efficient to perform high-frequency dielectric heating. .
In this case, there is no need to use high-frequency induction heating in conjunction with a weather strip embedded in a metal core. In other words, with metal core materials, the temperature of the core material is first raised by high-frequency induction heating, and then the temperature of the rubber is raised with high-frequency dielectric heating, but with synthetic resin core materials, the core material is heated together with the rubber using only high-frequency dielectric heating. Since the temperature can be raised, the rubber material can be sufficiently vulcanized to its center.

In addition, in the vulcanization process, the softened synthetic resin core material cannot be pulled out from the end of the process. 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.

In the weatherstrip obtained according to the present invention, a portion of the core material is continuous in the longitudinal direction, so that when the weatherstrip is assembled, no sagging or elongation occurs as in conventional weatherstrips. In particular, since the core material is made of synthetic resin, the continuous portion can be easily deformed, and the weather strip has good bending deformability.

[Example] Hereinafter, the present invention will be explained in detail with reference to Examples.

As shown in FIG. 1, the weatherstrip manufactured by the first manufacturing method of the present invention includes a base portion 11 having a U-shaped cross section and seal portions 12a and 12b. The base 11 has a retaining lip 13.

A core material 14 made of thermoplastic synthetic resin is embedded within the base portion 11 . As shown in FIG. 2, the core material 14 is
One side of the U-shaped cross section is a continuous part 14 in the longitudinal direction.
2, and the upper surface and other side surfaces are separated by slots 141 at predetermined intervals in the longitudinal direction. The weather strip 1 is assembled into the body opening so that the continuous portion 142 is on the inner diameter side of the corner. The rubber material of the base portion 11 is solid rubber, and the seal portions 12a, 12b are made of sponge rubber. Note that 144 is a hole for increasing the adhesion between the core material and the rubber.

Next, the third method for manufacturing the weather strip described above is described.
4 and 5.

As shown in FIG. 3, a portion along one end in the width direction forms a continuous portion 142 in the longitudinal direction, and the other portion is made of thermoplastic synthetic resin divided at predetermined intervals in the longitudinal direction by slots 141. A long plate-shaped core material 14 is used.

As shown in FIG. 4, first, in a core material feeding step, the core material 14 is fed from the cart 2. Next, in an extrusion molding step, the core material 14 is integrally extruded with the rubber material by the extruder 3. FIG. 5B shows an extrusion molded product, in which the core material 14 is wrapped in solid rubber.
Seal part 12 of sponge rubber from solid rubber
a and 12b protrude.

The extruded body is sent to a vulcanization process. That is, the extruded molded product is heated to about 120 to 150°C by a high-frequency dielectric heating device 4, and is vulcanized during the process of passing through a hot air tank 5 at about 200 to 220°C and keeping it warm. Unlike conventional methods, high frequency induction heating is not required.

Next, the extruded body is sent to an annealing tank 6 and heated to a temperature of 120 to 140°C.
The core material 14 is softened to a degree suitable for bending. Subsequently, in a base forming step, the solid rubber portion including the core material 14 is bent into a U-shaped cross section by a bending machine 9. FIG. 2 shows the cut 14 which has been bent. However, this figure shows the core material when the weather strip is attached to the corner.
During the manufacturing process, the core material 14 has a straight shape.

Next, the core material 14 is cooled in a cooling process by the cold air feeder 10
to stabilize the U-shape. FIG. 5C shows the weather strip obtained. Finally, cutting machine 1
1. Cut the weather strip to a predetermined length.

As shown in FIG. 9, the core material 14 to be extruded may be formed by bending one side of the core material shown in FIG. 3 in advance.

FIGS. 7 and 8 show a second manufacturing method of the present invention.

As shown in FIG. 7, a portion along one end in the width direction forms a continuous portion 142 in the longitudinal direction, and the central portion has slots 141 formed at predetermined intervals in the longitudinal direction. Along the other end, a small slot 141' is formed at the extension position of the slot 141, and these slots 141, 14
A narrow continuous portion exists between 1', and a core material 14 made of thermoplastic synthetic resin with a score line 143 formed therein is used for each continuous portion.

The steps of this method up to the vulcanization step are the same as the first manufacturing method. As shown in FIG. 8, the extruded body sent out from the hot air tank 5 is cooled in a cooling tank 6A,
The core material 14 is hardened or semi-hardened. Next, in the process of passing the core material 14 through the rollers of the core material separator 7, a bending stress in a direction perpendicular to the surface of the core material is applied to the solid rubber part surrounding the core material 14, and the core material 14 is broken at its score line 143 (FIG. 7).

Next, the extrusion molded body is heated in the preheating tank 8 and the core material 14 is heated.
is softened, and the solid rubber portion including the core material is bent into a U-shaped cross section using a bending machine 9. The following steps are the same as the first manufacturing method.

The resulting product is substantially the same as that produced by the first manufacturing method, except that there is a break 144 (FIG. 6) in the core material 14.

Note that in the second manufacturing method as well, it is possible to use a core material that is previously L-shaped as shown in FIG. In this case, the connection 1 that will be broken later
It is easier to apply stress when separating the core material if 44 is on the long side.

The second manufacturing method requires a few more steps than the first manufacturing method, in addition to the core material separation step. however,
In the core material in the first manufacturing method, during extrusion molding,
As shown in FIG. 10, deformation may occur in which the dividing portion inclines rearward with respect to the direction of travel (arrow). Since the core material in the second manufacturing method is connected on both sides in the width direction, such deformation does not occur.

As explained above, the weatherstrip manufactured according to the present invention does not stretch or sag when attached to a body opening, especially at a corner, and can easily be attached to a corner due to the shape and material of the core material used. Can be bent. The weather strip is also lighter.

According to the present invention, a weatherstrip having the above-mentioned excellent properties can be manufactured more easily and at lower cost than conventional weatherstrips in which a metal core is embedded by utilizing the softening property of the core material when heated.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a weather strip manufactured according to the present invention, FIG. 2 is a diagram showing an example of the core material in an embedded state, and FIG. 3 is a diagram showing the state of the core material in FIG. 2 before being embedded in the weather strip. The figure shown in Fig. 4 shows the manufacturing process (first step) of a weather strip using the core material shown in Fig. 3.
Figures 5A, B, and C are cross-sectional views taken along lines A-A, B-B, and C-C in Figure 4, respectively, and Figure 6 shows the core in the buried state. Figure 7 shows the state of the core material in Figure 6 before it is embedded in the weatherstrip. Figure 8 shows the manufacturing process of the weatherstrip using the core material in Figure 7. 2
9 is a perspective view showing a modified example of the core material in FIG. 7, FIG. 10 is a diagram showing twisting of the core material during extrusion molding, and FIGS. 11 to 13 are 11 is a cross-sectional view of the weather strip, FIG. 12 is a diagram showing the core material in the buried state, FIG. 13A is a plan view of the core material before being buried, and FIG. 13B is a cross-sectional view of the weather strip. It is a sectional view taken along the line BB in Figure A. 1... Weather strip, 11... Base, 12
a, 12b... Seal part, 14... Core material, 3...
Extruder, 4... High frequency dielectric heating device, 6... Annealing tank, 6A... Cooling tank, 7... Core material separator, 8...
Preheating tank, 9... Core material bending machine, 11... Cutting machine.

Claims (1)

[Scope of Claims] 1. A method for manufacturing an automobile weather strip comprising a base having a U-shaped cross section, a seal portion protruding from the base, and a core material embedded inside the base, the weather strip comprising a long length made of thermoplastic synthetic resin. A core material feeding process that feeds a core material that is plate-shaped and has a part of its width continuous in the longitudinal direction and the other part separated at predetermined intervals in the longitudinal direction; An extrusion molding step in which the core material and the rubber material are integrally extruded to obtain an extrusion molded product in which the core material is covered with rubber and the seal portion protrudes, and the extrusion molded product is heated and kept at a temperature to be vulcanized. A vulcanization process, a base forming process in which the extruded molded body containing the core material in a softened state is bent into a U-shaped cross section, a cooling process in which the weatherstrip with the base formed therein is cooled to stabilize its shape, and the weatherstrip is A method for manufacturing automotive weather strips, which comprises a cutting process of cutting the weather strips to a predetermined length. 2. A method for manufacturing a weather strip for an automobile, which has a base having a U-shaped cross section, a seal portion protruding from the base, and a core material embedded inside the base, the weather strip having a long plate shape made of thermoplastic synthetic resin, The center part is separated at a predetermined interval in the longitudinal direction, leaving both ends, one end is continuous in the longitudinal direction, and the other end can be broken at a predetermined interval in the longitudinal direction. A core material feeding step in which the core material is fed, and the fed core material and the rubber material are integrally extruded to obtain an extrusion molded body in which the core material is covered with rubber and the seal portion protrudes. An extrusion molding process, a vulcanization process in which the extrusion molded body is heated and kept warm, and vulcanized, a cooling process in which the vulcanized extrusion molded body is cooled, and a stress in the direction perpendicular to the core material surface is applied to the cooled extrusion molded body. a core material separation process in which the other end in the width direction is separated at a predetermined interval in the longitudinal direction, and a core material preheating process in which the extrusion molded body containing the core material is heated to soften the core material. , a base forming step in which the extrusion molded body containing the preheated core material is bent into a U-shaped cross section, a cooling step in which the weather strip with the base formed thereon is cooled to stabilize its shape, and a weather strip is formed into a predetermined length. A method for manufacturing automotive weather strips, which comprises a cutting process.