JPH0655388B2 - Method of manufacturing weather strip for automobile - Google Patents

Description

TECHNICAL FIELD The present invention relates to a weather strip used for an automobile.

[Prior Art] A weather strip that seals between a member for opening and closing the opening and the opening is installed along the opening of an automobile body or door. For example, as shown in FIG.
A weather strip 5 that seals the outer edge of the door glass 4 is attached to the inner periphery of the door frame 2.

The weather strip 5 is manufactured by extrusion molding, and has a body 50 having a U-shaped cross section and having seal lips 51 extending in opposite directions from both end edges on the opening side, as shown in FIG.
The holding lip 52 and the molding lip 5 which are flipped outward from the both edges and extend along both side surfaces of the main body 50.
Have three. Then, it is fitted into the retainer 3 formed in a channel shape along the inner circumference of the door frame 2, and the flanges 31 on both sides of the retainer 3 are provided between the holding lip 52 and the molding lip 53 and both side surfaces of the main body 50. It is assembled to the door frame 2 by sandwiching it (Japanese Utility Model Laid-Open No. 60-8373, JP-A-63-3425).
No. 9).

By the way, as shown in FIG. 10, the vertical portion of the door frame 2 is often of a type in which the thickness t is gradually increased downward. If a weather strip with a vertically uniform thickness of the molding lip 53 is attached, a step S is formed between the molding lip 53 and the outer surface of the door frame 2 to deteriorate the appearance.

Therefore, the weather strip main body 50 without the molding lip 53 is extruded, and the molding lip 53 having a gradually changing thickness is connected to the molding by molding. That is, as shown in FIG. 11, the weather strip body 50 is set in the mold 6 with its one edge facing the cavity 61, and as shown in FIG. Rubber or synthetic resin is injected to mold the molding lip 53.

[Problems to be Solved by the Present Invention] However, in the weather strip formed by molding the molding lip 53 as described above, as shown in FIG. 13, between the molding lip 53 and the side surface portion 55 of the main body which faces the molding lip 53. The gap C of is wider than the gap set by the mold,
Often. When the weather strip is widened, as shown in FIG. 14, when the weather strip is attached to the door frame 2, the gap C between the molding lip 53 and the flange 31 of the retainer 3 formed on the door frame 2 opens. As a result, the sealability is deteriorated and the appearance is impaired.

Therefore, as a countermeasure for this, a means for narrowing the gap C when molding the molding lip 53 can be considered, but if it is attempted to narrow it, the mold portion 62 shown in FIG. 11 must be thinned. In terms of strength, it cannot be thinner than the current thickness.

The present invention has been made in view of the above circumstances, in a weatherstrip in which a molding molding lip is connected to an extrusion molding weatherstrip body, without modifying the mold, the molding lip and the side surface of the main body. It is an object of the present invention to provide a method for manufacturing a weather strip in which the gap between the strips can be narrowed so that the opening does not occur.

[Means for Solving the Problem] As a result of various experiments conducted by the inventors, the following facts were found as a result of various causes regarding the cause of the molding lip of the molding being opened more than the set shape of the mold.

That is, as shown in FIG. 11, the weather strip body 50
When the mold 6 is set and the material is injected into the cavity 61, the material pressure acts on the molding lip connecting surface 54 of the main body 50, but this pressure does not always act uniformly on the connecting surface 54. Depending on the injection conditions, variations in the extrusion shape of the connection surface 54 and the end edge portion, etc., the inner portion of the connection surface 54 may be pushed by the material pressure, as shown in FIG. To do. Then, when the inner portion is pushed in, when the weather strip is taken out after molding, the particularly strongly compressed inner portion is restored to its original shape, and as a result, the molding lip 53 is centered on the root of the main body 50. In contrast to this, it rotates in the direction of arrow A and the gap C widens as shown in FIG.

The present invention is based on such knowledge, and when the weather strip main body 50 is extrusion-molded as shown in FIGS. 4 and 5, the molding lip connecting surface 54 at the edge of the weather strip main body 50 has a notch portion on the outer side thereof. 541 is formed, and as shown in FIG. 6, the above-mentioned edge is formed in the molding cavity 61 for molding,
The injection material pressure acts on the notch 541 so that the end edge is compressed in the thickness direction, and the molding lip 53 is connected to the end edge by molding as shown in FIG. Characterize.

[Operation and Effect] When the molding of the molding lip 53 is performed, the pressure of the injected material acts on the cutout portion 541 as shown in FIGS. 6 and 7, and the edge portion where the cutout portion 541 is formed is thick. Compressed in the vertical direction. In particular, the tip side is greatly compressed. As a result, when the weather strip is taken out of the mold and the tip side returns to its original shape, the molding molding lip 53 rotates in the direction of the main body 50, and as shown in FIG. The gap C becomes narrower than the gap width set by the mold. As a result, the above-mentioned mouth opening unlike the conventional case does not occur.

[Embodiment] The present invention will be described with reference to an embodiment applied to the production of a weather strip 5 attached along the inner circumference of a door frame 2 as shown in Fig. 1, particularly a vertical portion thereof.

The weather strip 5 is made of rubber and has a U-shaped cross section and a sealing lip 51 extending inward from both end edges of the opening and a holding lip 52 extending outward from one end edge as shown in FIG. The main body 50 and a molding lip 53 that extends outward from the other edge and extends along the side surface of the main body 50.
Is equipped with. In the vertical portion of the weather strip 5, the molding lip 53 is gradually thickened downward.

Next, a method of manufacturing the vertical portion of the weather strip 5 (hereinafter, referred to as a weather strip at the end) will be described.

Main body 50 shown in FIG. 3 having a uniform cross-sectional shape in the longitudinal direction.
Is extruded. At this time, the molding lip connecting surface 54 at the other end of the main body 50 is formed into a surface having a stepped notch 541 on the outer side, as shown in FIG. As shown in FIG. 5, the cutout portion 541 may be an inclined surface whose end edge tip side becomes thinner.

As shown in FIG. 6, the main body 50 thus obtained is orthogonal to the flow direction of the injection material in the bent portion of the cavity 61 having the other end on which the connection surface 54 is formed and forming the molding lip 53. Face the direction and set in the mold 6.
The width of the cavity 61 is gradually widened downward. Then, a rubber material is injected into the cavity 61 as shown in FIG. 7, and the connection surface 5 having the cutout portion 541 is formed.
The molding lip 53 connected to No. 4 is molded.

In this case, the rubber material flows in the direction of the arrow shown in FIG. 6, and pressure acts on the entire connecting surface 54 having the cutout portion 541. Particularly, in the notch portion 541, pressure acts in the thickness direction of the end portion of the main body to compress the end edge portion, and particularly the tip side is largely compressed, and the molding lip 53 is connected in this compressed state.

When the weather strip to which the molding lip 53 is connected in this manner is taken out by opening the mold 6, the molding strip 53 is removed.
The compressive force is released from the end edge portion of the main body 50 to which is connected and the original shape is restored. As a result, the molding lip 53 rotates in the direction of arrow B in FIG. 8 about its root. As a result, the gap C between the side surface 55 of the main body 50 and the molding lip 53
Is smaller than the thickness of the mold part 62 (FIG. 7).

Therefore, in the weather strip obtained by the present invention, the gap C can be made sufficiently small without modifying the mold. Therefore, when this is attached to the door frame, the molding lip 53 is in close contact with the door frame 2 without opening the gap C unlike the conventional example shown in FIG. 14, and a sufficient sealing property and a good appearance are obtained. Be done.
Further, the connection surface 54 of the molding lip 53 is widened by forming the cutout portion 541, which also has the effect of increasing the bonding strength.

[Brief description of drawings]

FIG. 1 is a front view of an automobile door equipped with a weatherstrip, and FIGS. 2 to 8 show an embodiment of the present invention. FIG. 2 is a main part of the weatherstrip obtained by the present invention. FIG. 3 is a perspective view, FIG. 3 is a cross-sectional view of a weatherstrip body extruded, FIGS. 4 and 5 are views showing the shape of a molding lip connecting surface, and FIG. FIG. 7 is a view showing a state where the molding is performed, and FIG. 7 is a cross-sectional view of the weather strip taken out from the mold, taken along the line VIII-VIII in FIG. 9 to 14 show a conventional example.
Fig. 1 is a cross-sectional view of a conventional weather strip in a mounted state at a position along the line IX-IX in Fig. 1, Fig. 10 is a diagram showing a problem in a mounted weather strip, and Fig. 11 is a molding lip. FIG. 12 is a view showing a state where the weather strip body is set in a mold for molding, FIG. 12 is a view showing a state where a molding lip is formed, FIG. 13 is a sectional view of a molding lip molding portion, and FIG. 14 is a molding. It is an installation state sectional view of a lip formation part. 1 …… Automobile door 2 …… Door frame 31 …… Flange 4 …… Door glass 5 …… Weather strip 50 …… Main body 53 …… Mall lip 54 …… Mall lip connection surface 541 …… Notch 6 …… Mold 61 …… Cavity

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-58-163636 (JP, A) JP-A-63-77720 (JP, A)

Claims (1)

[Claims] 1. A weather strip body having a molding lip which is turned outward from an edge of the weather strip body and extends along a side surface of the body. The side surface of the body and the molding lip hold the weather strip. A method of manufacturing a weather strip for an automobile in which a caulking flange is sandwiched, wherein a method of connecting the molding lip to the extrusion-molded body by molding, the outside of the molding lip connecting surface of the edge Extrusion molding a weatherstrip body with a notch formed in the part, set the edge of the weatherstrip body extruded into the cavity of the mold to be molded with the molding lip, and mold the molding lip with the above-mentioned cavity. Injected into
Manufacture of a weather strip for automobiles, characterized in that the edge is compressed in the thickness direction by the pressing pressure of the molding material acting on the notch, and the molding lip is connected to the edge. Method.