JP4012105B2 - Weather strip corner molding method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a molding method for molding a corner portion of the weather strip for an automobile having a hollow seal portion.
[0002]
[Prior art]
Conventionally, an automotive weather strip 20 having a hollow seal portion 21 has a straight portion formed by extrusion and a corner portion C formed by molding (see FIG. 5). In this case, since a connection mark (line) S is formed at the boundary portion between the extruded product E and the molded product M, it is not preferable in appearance. In addition, since the hollow seal portion 21 is formed by using the center core, it is necessary to form a center core punching hole 22 in the hollow seal portion 21 (see FIG. 6). It is necessary to close the hole 22 with an adhesive. Furthermore, since it is necessary to mold both the extruded product E and the molded product M, the molding operation is troublesome.
[0003]
For this reason, a means has been devised in which the whole is formed of an extrusion-molded product E, and the corner portion C is heated in a molding die, and is molded by so-called heat brazing.
The molding die 40 used for this means includes a first split mold 41, a second split mold 42, a third split mold 43, a fourth split mold 44, and a fifth split mold 45. A press-fit split mold part 46 that is press-fitted into the base part 31a of the hollow seal part 31 is provided at the tip part (see FIG. 7). The wall thickness t of the press-fit split mold portion 46 is lower than the height of the hollow seal portion 31 (approximately 1/7 in the case of FIG. 7) so as to be easily press-fitted into the base portion 31a. Is set to
[0004]
[Problems to be solved by the invention]
However, when this conventional molding die 40 is used to heat and heat the extrusion-molded product E, wrinkles are generated in the hollow seal portion 31 when the extrusion-molded product E is set in the molding die 40. The crease W is generated in the product (see FIG. 8).
[0005]
Therefore, an object of the present invention is to provide a method for forming a corner portion of a weather strip that can form a corner portion that is not creased by heat-curing the extruded product.
[0006]
[Means for Solving the Problems]
To achieve the above object, the invention according to claim 1 of the present invention, through two root portions against one side wall of the substantially U-shaped cross section of the mounting base (3) and (2a, 2b) The automotive weather strip (1) having the hollow seal portion (2) attached in this manner is formed by extrusion molding, and a molding die (10) is formed in a state where a part of the extrusion molded product (E) is curved. is set to, subjected Paste was hot, a corner portion forming method of a weather strip forming a corner portion (C),
Of the two root portions (2a, 2b), the root portion (2a) of the hollow seal portion (2) located inside the corner portion (C) and one side wall of the mounting base portion (3) The tip of the press-fit split mold part (16) constituting the molding die (10) to be press-fitted in between is made into a substantially rectangular cross section, and the thickness (T) of the tip of the press-fit split mold part (16) , said hollow seal part (2) to the crease (W) is thicker in the size that does not occur, the root portion located inside of the corner portion of the hollow seal portion (2) (C) (2a) The corner portion (C) of the weather strip (1) is formed so as to lift the part (2c) to be continuously provided.
[0007]
Although the magnitude | size which a crack (W) does not generate | occur | produce in a hollow seal part (2) cannot be strictly limited, at least thickness (t) of the press-fitting split mold part (46) of the conventional molding die shown in FIG. It is about 2-3 times larger.
[0008]
In the invention according to claim 2, the thickness (T) at the center of the corner portion (C) of the press-fit split mold portion (16) is gradually increased from the thickness at the start of the corner portion (C). It is characterized by being set to.
[0009]
Furthermore, in the invention described in claim 3, the thickness (T) of the press-fit split mold part (16) is set to be 1/2 of the height of the hollow seal part (2) at least at the center of the corner part (C). It is characterized by being set to a degree .
[0012]
Symbols in parentheses indicate corresponding elements or corresponding matters described in the drawings and embodiments of the invention described later.
[0013]
According to the invention described in claim 1 of the present invention, the press-fitting split mold part to be press-fitted into the base part of the hollow seal part is formed into a substantially rectangular cross section inside the corner part, and the thickness thereof is set to the hollow seal part. It is set to a size that does not cause creases (about 2 to 3 times the conventional size), and the part connected to the base of the hollow seal is lifted to prevent the occurrence of seal flaws. In addition, it is possible to provide a weather strip for automobiles having an excellent appearance.
[0014]
That is, by setting the thickness of the press-fitting split mold part to be about 2 to 3 times larger than the conventional thickness, the base part of the hollow seal part is bent so as to be along the corner part. Therefore, the stretched portion is only restored to the original state, and the contracted state is avoided, so that it is considered that the occurrence of creases can be prevented.
[0015]
In addition, since the weatherstrip formed by this molding die is entirely an extrusion-molded product, no connection trace is formed between the extrusion-molded product and the molded product as in the prior art, and the core No through hole is formed. Accordingly, the appearance is excellent and the molding operation is easy.
[0016]
According to the invention described in claim 2, in addition to the operational effects of the invention described in claim 1, the thickness at the center of the corner portion of the press-fitting split mold portion is gradually increased from the thickness at the start of the corner portion. Further, according to the invention of claim 3, the thickness of the press-fit split mold part is set to about ½ of the height of the hollow seal part at least in the center of the corner part. Therefore, the occurrence of creases can be prevented more reliably.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1 and FIG. 2, the corner part shaping | molding method which concerns on embodiment of this invention performed using the corner part shaping die 10 which concerns on 1st embodiment of this invention is demonstrated. FIG. 1 is a perspective view showing a corner portion C of a weather strip 1 molded by a molding die 10 and a molding method according to the first embodiment of the present invention, and FIG. 2 is a molding according to the first embodiment of the present invention. 1 is a cross-sectional view showing a mold 10. The same parts as those shown in the conventional example are denoted by the same reference numerals.
[0020]
The corner part forming method according to the first embodiment of the present invention is used for forming a weather strip 1 for an automobile having a hollow seal part 2 and a mounting base part 3 having a substantially U-shaped cross section. The hollow seal portion 2 is attached to the attachment base portion 3 through base portions 2a and 2b.
In this molding method, first, the entire weather strip 1 is molded by extrusion molding. Next, a part of the extruded product E is bent and set in the molding die 10 and heated to approximately 180 ° C. to 210 ° C. to be heat-cured to form a corner portion C. In this embodiment, the weather strip 1 is made of EPDM material, but is not particularly limited.
[0021]
Here, it is assumed that the molding die 10 used for this heat brazing has a press-fit split mold part 16 for press-fitting into the base part 2a of the hollow seal part 2 located inside the corner part C, and the press-fit split mold part 16 has a substantially rectangular cross section, and the thickness T of the press-fitting split mold portion 16 is set to a thickness that does not cause the wrinkle W in the hollow seal portion 2. And the site | part 2c connected with the base part 2a of the hollow seal part 2 is lifted by the thickness T of the press-fit split mold part 16.
In the present embodiment, the thickness T is approximately half the height of the hollow seal portion 2 at the center X of the corner portion C and is substantially equal to the height of the second split mold 12 described later. It is set and gradually decreased toward both ends Y and Z that become the start of the corner C that changes from a straight line to a curved line. This reduction in size may be set linearly (FIG. 3A) or may be set curved (FIG. 3B).
[0022]
The molding die 10 in the present embodiment includes a first split mold 11, a second split mold 12, a third split mold 13, a fourth split mold 14, and a fifth split mold 15, and the outer shape of the weather strip 1 Is shaped like The press-fit split mold part 16 is provided at the upper end of the fifth split mold 15.
[0023]
As shown in FIG. 1, the weather strip 1 according to the present embodiment has a thickness T of the press-fitting split mold portion 16 that is press-fitted into the root portion 2 a of the hollow seal portion 2 inside the corner portion C. Since it is molded by the molding die 10 according to the above embodiment, which is thickly set to a size that does not cause the crease W, the crease W does not occur in the appearance and is excellent in appearance.
[0024]
Further, since the entire weather strip 1 is an extrusion-molded product E, no connection trace S is formed between the extrusion-molded product E and the molded product M, and there is no center core hole. Not formed. Therefore, the appearance is excellent and the molding is easy.
[0025]
Next, with reference to FIG. 4, the corner part shaping die 10 which concerns on 2nd embodiment of this invention is demonstrated. FIG. 4 is a cross-sectional view showing the corner portion molding die 10.
The molding die 10 is characterized in that a press-fitting recess 16 a into which the inner lower end portion of the corner portion C of the hollow seal portion 2 is press-fitted is formed in the press-fitting split die portion 16, and the upper end of the tip portion has a bowl shape. By forming the press-fit recess 16a, the gap G between the inner lower end portion of the hollow seal portion 2 and the mounting base portion 3 can be set to the same level as that of portions other than the corner portion C. Therefore, it is possible to provide the weather strip 1 that is further excellent in appearance. In the present embodiment, the gap G is approximately ½ of the wall thickness T of the press-fit split mold part 16.
[0026]
【The invention's effect】
According to the invention in Claim 1 of the present invention, the inside of the corner portion, thicker setting the thickness of the press-split mold portion for press-fitting the base portion of the hollow seal portion, sized to wrinkles Slight hollow seal portion does not occur Therefore, it is possible to provide a weather strip for automobiles having an excellent appearance.
In addition, since the weatherstrip formed by this molding die is entirely an extruded product, no connection trace is formed between the extruded product and the molded product as in the prior art. No through hole is formed. Accordingly, the appearance is excellent and the molding operation is easy.
[0027]
According to the invention described in claim 2, in addition to the operational effects of the invention described in claim 1, the thickness at the center of the corner portion of the press-fitting split mold portion is gradually increased from the thickness at the start of the corner portion. Further, according to the invention of claim 3, the thickness of the press-fit split mold part is set to about ½ of the height of the hollow seal part at least in the center of the corner part. Therefore, the occurrence of creases can be prevented more reliably.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an essential part inside a corner portion of a weather strip according to an embodiment of the present invention.
FIG. 2 is a sectional view showing a molding die according to the first embodiment of the present invention.
FIG. 3 is a view showing a change in thickness of a press-fitting split mold part of the molding die according to the first embodiment of the present invention.
FIG. 4 is a cross-sectional view showing a molding die according to a second embodiment of the present invention.
FIG. 5 is a perspective view showing a main portion inside a corner portion of a weather strip according to a conventional example.
6 is a perspective view showing an outer corner main part of the weather strip shown in FIG. 5; FIG.
FIG. 7 is a cross-sectional view showing another weatherstrip molding die according to a conventional example.
FIG. 8 is a perspective view showing a main part outside the corner part of another weather strip according to a conventional example.
[Explanation of symbols]
1 Weather Strip 2 Hollow Seal 2a Base (corner side)
2b Base part 2c Site 3 connected to base part 2a 3 Mounting base 10 Mold 11 First split mold 12 Second split 13 Third split 14 Fourth split 15 Fifth split 16 Press split mold 16a Press-fit recess 20 Weather strip 21 Hollow seal portion 22 Centering hole 30 Weather strip 31 Hollow seal portion 31a Base portion 31b Base portion 40 Molding die 41 First split die 42 Second split die 43 Third split die 44 Fourth split Mold 45 50% mold 46 Press-fit split mold part C Corner part E Extrusion product G Gap M Mold product S Connection trace T, t Wall thickness W Folding ridge X Center Y, Z End

Claims (3)

A whole automotive weather strip having a hollow seal portion attached to one side wall of a mounting base portion having a substantially U-shaped cross section through two root portions is formed by extrusion molding, and a part of the extruded product Is set to a molding die in a curved state, and then subjected to heat brazing to form a corner portion of a weather strip ,
Of the two root parts, a press-fit split mold part constituting the molding die that is press-fitted between the root part of the hollow seal part located inside the corner part and one side wall of the mounting base part. with the tip with a substantially rectangular shape in cross section, its thickness of the tip of the press-split mold portion, the wrinkles Slight hollow seal portion is thicker in the size that does not occur, the inside of the corner portion of the hollow seal portion root so as to lift the site continuously provided to the unit, the corner portion forming method of a weather strip, which comprises forming a corner portion of the weather strip located. 2. The corner formation of a weather strip according to claim 1, wherein the thickness at the center of the corner portion of the press-fitting split mold portion is set to gradually increase from the thickness at the start of the corner portion. Way . The weather strip corner according to claim 1 or 2, wherein the thickness of the press-fitting split mold part is set to about ½ of the height of the hollow seal part at least in the center of the corner part. Part molding method .

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