JPH0212778B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a weather strip for an automobile, and more particularly to a weather strip structure having a welt portion that fits into a flange of a vehicle body panel.

Conventional technology Conventional automotive weather strips include:
There is a structure shown in FIG. That is, the weather strip 1 is composed of a welt portion 2 and a seal lip 3. The welt portion 2 has a substantially U-shaped cross section, and a metal core material 4 is embedded therein. On the other hand, the seal lip 3 is integrally provided on the outer peripheral surface of the welt portion 2 so as to extend along the bent portion 2a.

When manufacturing such a weather strip 1, first, solid rubber for forming the welt portion 2,
The sponge rubber forming the seal lip and the flat core material 4 are triple extruded to obtain a molded product with a flat welt portion 2 as shown in FIG.

Next, as a result, the core material 4 embedded in the welt part 2 is cut into the notches 5 formed at regular intervals.
Separate each part to make it discontinuous. Thereafter, in a bender process, the welt portion 2 is bent into a substantially U-shaped cross section as shown in FIG.

However, in the weather strip 1, the welt portion 2 bends around the core material 4 and follows the curved shape of the core material 4 during the bender process. At this time, since the core material 4 is embedded within the welt portion 2 and is discontinuous, it is difficult to form the bent line accurately on a constant line. Therefore, as described above, the bent portion 2a of the welt portion 2, which follows the bent shape of the core material 4, may be formed at a position displaced from a fixed straight line.
On the other hand, an outer layer 2b outside the core material of the welt portion 2
In this case, tension is generated in the outer line direction (A and B directions in FIG. 2) with the bent portion 2a as the center, and the protruding direction of the seal lip 3 is determined by the balance of this tension.

Therefore, when the bent portion 2a is displaced from a certain line, the tension becomes unbalanced, and the first
As shown by the broken line in the figure, there are cases where the direction in which the seal lip protrudes is not constant.

This makes it difficult to keep the sealing surface of the seal lip 3, sealing reaction force, etc. constant, resulting in the disadvantage that uniform sealing characteristics cannot be obtained.

Purpose of the Invention The present invention was made in view of the actual situation of conventional weather strips, and by making the protruding direction of the seal lip constant, the seal surface and seal reaction force are made uniform. It is an object of the present invention to provide a weather strip structure for an automobile that can improve sealing characteristics.

Structure of the Invention In order to achieve the above object, the present invention includes the following:
The welt part has a U-shaped cross section and has a core material embedded therein, and a seal lip integrally protrudes from the outer circumferential surface of the welt part along the bent part, and the welt part is extruded in an expanded state. After that, in the weather strip that is bent and formed into the cross-sectional shape, the weather strip has a hollow shape in the unfolded state between the protruding base of the seal lip and the outer peripheral surface of the welt part;
A hollow portion is provided that is closed as the bent portion deforms during bending.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. In other words, as shown in Figures 3 and 4,
The weather strip 11 includes a welt portion 12 for fitting into a flange formed on a vehicle body panel. The welt portion 12 is made of solid rubber, and a metal core material 14 in which cuts 13 are formed at equal intervals is embedded therein. A seal lip 15 is provided protruding from the outer peripheral surface of the welt portion 12, and the seal lip 15 is connected to the surface layer 16.
It is also molded from sponge rubber. Between the protruding base of the seal lip 15 and the outer peripheral surface of the welt portion 12, a hollow portion 17 is formed along the bent portion 12a.
is formed. The hollow portion 17 forms a cavity H when the welt portion 12 is unfolded as shown in FIG. 3, and the welt portion 12 is bent to have a U-shaped cross section as shown in FIG. At this time, as the bent portion 12a of the welt portion 12 deforms, the cavity H is closed and the slit S is formed.

Note that 18 in the figure is a retaining lip formed on the inner circumferential surface of the welt portion 12.

Next, the weather strip 11 according to the above configuration
The molding process will be explained. First, as shown in FIG. 3, a flat core material 14 and a welt part 1 are
2. Solid rubber for forming the retaining lip 18 and sponge rubber for forming the sealing lip 15 and surface layer 16 are triple extruded to obtain a molded product with the welt portion 12 expanded as shown in FIG.
At this time, the hollow portion 13 is formed so that the hollow H is formed during extrusion molding. Next, the core material 14 embedded in the welt portion 12
is divided through the notch 13. Furthermore, in the next bender process, the welt portion 12 is bent to have a substantially U-shaped cross section as shown in FIG. At this time, the hollow portion 17 is located at the welt portion 1 as described above.
Since it is formed along the second bent portion 12b, the bent portion 12 is gradually closed as the bent portion 12 expands due to the bending. When this bending process is completed, the hollow part 17 becomes a slit S-shape, and the tension in the directions A and B described above is absorbed by the deformation of the hollow part 17. Therefore, even if the bending line of the core material 14 is displaced from a fixed line and the tension in the front A and B directions becomes unbalanced due to this,
It is possible to prevent the protruding direction of the seal lip 15 from being displaced from a fixed line. Therefore, by displacing the seal lip 15 in the protruding direction, it is possible to prevent seal reaction force and non-uniformity of the seal surface, and to improve seal characteristics.

Effects of the Invention As explained above, the present invention provides that the welt part has a hollow shape in the unfolded state between the protruding base of the seal lip and the outer peripheral surface of the welt part, and the welt part is closed as the welt part is deformed by bending. A hollow portion is provided, and the tension generated at the proximal end of the seal lip during the bending process is balanced by the deformation of the hollow portion. Therefore, even if the bent portion of the welt portion is bent and formed in a state where it is displaced from a fixed line, the direction in which the seal lip protrudes can be maintained on a fixed line. Therefore, the sealing reaction force of the seal lip and the sealing surface can always be kept on a constant line, and the sealing characteristics can be improved.

In addition, in the present invention, since the direction in which the seal lip protrudes can be kept constant without being affected by the bent state of the welt part, the weather strip can be attached to the corner of the opening edge of the vehicle body. Even when the weather strip is attached to the weather strip, the direction in which the seal lip protrudes can be kept constant, thereby increasing the degree of freedom in designing the weather strip attachment site.

[Brief explanation of drawings]

FIG. 1 is a partially cross-sectional perspective view showing an example of a conventional weather strip, and FIG. 2 is a plan view showing the welt part of the same weather strip in an expanded state.
FIG. 3 is a perspective view showing a state in which the welt part of a weather strip according to an embodiment of the present invention is unfolded;
FIG. 4 is a partially sectional perspective view of the weather strip. 11... Weather strip, 12... Welt part, 12b... Bent part, 13... Notch, 1
4...Core material, 15...Seal lip, 17...Hollow part.

Claims (1)

[Claims] 1. A welt part having a substantially U-shaped cross section and having a core material embedded therein, and a seal lip integrally protruding from the outer peripheral surface of the welt part along a bent part,
In the weather strip which is formed by forming the welt part in the unfolded state and then bending it into the cross-sectional shape, the weather strip has a hollow shape in the unfolded state between the protruding base of the seal lip and the outer peripheral surface of the welt part. A weather strip structure for an automobile, characterized in that a hollow part is provided which is closed as the bent part deforms during bending.