JP2001055096A - Weather strip for seal hood - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a weather strip for a seal hood and manufacture thereof which have achieved a low cost, lightweight and recycle property in comprison with conventional ones. SOLUTION: This is the weather strip 1 for a seal hood formed by a thermo plastic elastomer. Its shape is provided with an installation base part 1a installed to the caul panel of a car body and a hollow seal part 1b press-contacted with the lower surface of a hood. The sectional shape of the installation surface of the installation base part 1a is formed in such shape that its end part is projected than its center part 1c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a weather strip for a seal hood.

[0002]

2. Description of the Related Art As shown in a perspective view of an automobile shown in FIG. 1, a front end portion of a cowl panel 2 provided to cover an upper portion of a cowl is pressed against a lower surface of a rear portion of a bonnet 3 so as to be pressed. A weather strip 1 for a seal hood (hereinafter, may be simply referred to as a weather strip) is attached to seal a gap between the vehicle and the vehicle body. Conventionally, a rubber foam has been used as a material for forming the weather strip.

[0003]

However, the recent trends in the development of automobiles include low cost, low weight, and recyclability. However, using a rubber foam to achieve these problems is not enough. There was a limit.

[0004] It is an object of the present invention to provide a weather strip for a seal hood, which has achieved lower cost, lower weight, and recyclability than before, and a method of manufacturing the same.

[0005]

In order to achieve the above object, a weather strip for a seal hood according to the present invention is formed of a thermoplastic elastomer foam,
A mounting base attached to the vehicle body, and a hollow seal portion pressed against the lower surface of the bonnet, wherein a cross-sectional shape of the mounting surface of the mounting base is formed in a shape in which both end portions are more protruded than the central portion. It is characterized by having.

When the weatherstrip is formed of a rubber foam, the specific gravity is about 0.65, and when the weatherstrip is formed of a thermoplastic elastomer foam, it is about 0.5. Therefore, it is possible to achieve a weight reduction of about 15% as compared with the related art. In addition, since thermoplastic elastomers can be molded and processed by a plastic molding apparatus, products can be manufactured without a kneading step and a vulcanizing step, and thus are superior in cost as compared with rubber foams. Further, in terms of recyclability, the thermoplastic elastomer foam is superior to the rubber foam.

As described above, by using a thermoplastic elastomer foam, it was possible to provide a weather strip for a seal hood achieving low cost, low weight and recyclability.

The shape of the weather strip for a seal hood includes a mounting base mounted on the vehicle body, and a hollow seal portion pressed against the lower surface of the bonnet. Since both ends are formed in a protruding shape than when the weather strip is attached, both ends have stronger surface pressure than the central part of the attachment surface, and the sealing effect can be enhanced. .

As a specific configuration in which both end portions protrude from the center portion, projections are formed at the both end portions. Therefore, when the weather strip is attached, the projection portions are deformed. Thus, a desired sealing property can be secured.

A clip for attaching a weather strip is attached to the attachment base, and a head inserted into the hollow seal portion is attached to the clip, and the clip cooperates with the head. It is preferable that a collar for holding the mounting base is provided.

Furthermore, it is preferable that the dimension between the pair of projections at both ends is set to be larger than the dimension of the collar.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a weather strip for a seal hood according to the present invention will be described with reference to the drawings.

<First Embodiment> FIG. 1 is a perspective view of an automobile, in which a cowl panel 2 provided so as to cover an upper part of a cowl has a front end portion pressed against a rear lower surface of a bonnet 3. Then, a weather strip 1 for a seal hood is attached to seal a gap between the hood 3 and the vehicle body. The weatherstrip 1 extends longitudinally along the front end. Weather strip 1
It is formed by a thermoplastic elastomer foam.

The following can be used as the thermoplastic elastomer (hereinafter referred to as TPE). That is, as a polystyrene-based TPE (SBC), a styrene-butadiene-styrene block copolymer (SB
S), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SE
PS) and the like, and polyolefin-based TPE (TPO) includes a simple blend type (s-TPO), an implanted TPO (i-TPO), a dynamic vulcanization type (TPV) and the like.

[0015] In any case, polypropylene (PP) or polyethylene (PE) is mainly used for the hard segment, and EPDM, NBR, etc. are mainly used for the soft segment.

The polydiolefin-based TPE includes syndiotactic-1,2 polybutadiene (RB) -based TPE.
PE, trans-polyisoprene (TPI) -based TPE, natural rubber-based TPE (TPNR), and the like. Chlorine-based TPEs are polyvinyl chloride-based TPEs, ie, PVC-based TPEs (TP
VC) and chlorinated polyethylene.

Further, engineering plastic type TPE, polyurethane type (TPU) TPE, polyester type (TPEE) TP
E, polyamide-based (TPA) TPE, fluorine-based TPE, and the like.

In an extruder for producing the weatherstrip 1, a polyolefin-based TPE is used in that a good foam can be formed using water which is a foaming agent having no environmental problem. It is particularly preferable to use a polyolefin-based TPE in which a vulcanized rubber such as butyl rubber, isoprene rubber, EPDM, natural rubber, butadiene rubber, or SBR is dispersed in PP or the like in the form of particles.

FIG. 2A is a sectional view of the weather strip 1 cut along a plane perpendicular to the longitudinal direction. The weatherstrip 1 includes a mounting base 1a that is mounted to the cowl panel 2 and a hollow seal portion 1b that is deformed by being pressed against the lower surface of the rear end of the bonnet 3.

As shown in FIG. 2, the weather strip 1
Mounting clips 4 at predetermined intervals along the longitudinal direction of the
Is provided. The clip 4 is a well-known clip, and includes a head 4a inserted into the hollow seal portion 1b,
Collar 4b for holding mounting base 1a in cooperation with head 4a
And a retaining portion 4c for preventing the weather strip 1 from coming off when the clip 4 is inserted into the hole formed in the cowl panel 2.

Further, the mounting base 1 of the weather strip 1
In the figure, a has a central portion 1c of which the shape on the mounting side with respect to the cowl panel 2 is a flat surface, and a pair of protrusions 1d formed at both ends of the central portion 1c. FIG. 2B is an enlarged view of the protrusion 1d, and the radius R of the tip is 0.75 mm.
Below (1.5 mm or less in diameter), and the height H is 1.5
mm or less.

If the radius R of the tip is increased, the surface pressure acting on the projection 1d is reduced and the sealing performance is also reduced. Therefore, the radius R of the tip is desirably 0.75 mm or less. Further, the height H is desirably 1.5 mm or less. If the height is too high, the rigidity of the projection 1d is also reduced, and the desired sealing property cannot be secured. However, the height of the clip 4 needs to be higher than the flange 4b.

When the weather strip 1 is manufactured by TPE in which the above-described vulcanized rubber is dispersed, the temperature of the cylinder portion of the extruder is usually adjusted to 170 to 180 ° C. and the temperature of the head and the die portion to 180 to 185 ° C. The weather strip 1 having a desired shape can be manufactured by injecting water near the center of the portion and foaming the water simultaneously with the extrusion. At this time, the protrusion 1d of the extrusion molding die
Is formed at 200 ° C. to 2 ° C. with a heat source such as a sheath heater.
20 ° C. (+15 to +40 for portions other than the protrusion 1d)
° C; +20 to + 50 ° C with respect to the cylinder). When the temperature is set to 190 ° C. or lower, the protrusion 1d is in a state of being crooked, and the sealing property is reduced. 20
By setting the temperature at 0 ° C. or higher, the surface state of the projections becomes smooth, and good sealing properties can be secured.

FIG. 3 is a view showing a state in which the weather strip 1 is mounted on the mounting surface 2 a of the cowl panel 2.
Attach the clip 4 to the mounting surface 2a of the cowl panel 2.
This is performed by inserting it into the hole formed in the hole. Clip 4
Of the hole formed in the attachment portion 2a of the cowl panel 2 so that the weather strip 1 is attached so as not to come off. When the projection 1d is deformed in the mounted state, the sealing property is ensured.

<Structure of Second Embodiment> FIG. 4 shows the shape of a weather strip 1 according to a second embodiment. The central portion 1c and the pair of projecting portions 1e at both ends are connected by a gentle curve. Even with such a shape, desired sealing properties can be ensured.

[Brief description of the drawings]

FIG. 1 is a perspective view of an automobile.

FIG. 2 is a cross-sectional view when the weather strip according to the first embodiment is cut along a plane orthogonal to a longitudinal direction.

FIG. 3 is a view showing a state in which the weather strip 1 is mounted on a mounting surface 2a of the cowl panel 2;

FIG. 4 is a cross-sectional view when the weather strip according to the second embodiment is cut along a plane orthogonal to the longitudinal direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Weather strip 1a Mounting base 1b Hollow seal part 1c Central part 1d Projection 2 Cowl panel 3 Bonnet 4 Clip H Height R Radius

Claims (4)

[Claims] 1. A mounting base formed of a thermoplastic elastomer foam, mounted on a vehicle body, and a hollow seal portion pressed against a lower surface of a bonnet, wherein a mounting surface of the mounting base has a cross-sectional shape. A weather strip for a seal hood, wherein both ends are formed in a shape protruding more than a center part. 2. The weather strip for a seal hood according to claim 1, wherein projections are formed at both ends. 3. A weather strip mounting clip is attached to the mounting base, and a head inserted into the hollow seal portion is provided on the clip, and the head cooperates with the head. The weather strip for a seal hood according to any one of claims 1 to 2, further comprising a collar portion for clamping the mounting base portion. 4. The weather strip for a seal hood according to claim 3, wherein a dimension between the pair of projections at both end portions is set to be larger than a dimension of the collar portion.