JP3005930B2 - Method of manufacturing weather strip - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a weather strip in which an extruded part and a molded part are integrally connected. Here, the weather strip is a concept including a window weather strip (window frame rubber), a glass run, a door weather strip, and the like.

[0002]

2. Description of the Related Art Here, a case where a corner portion of a window frame rubber is formed will be mainly described. However, the same applies to other types of weather strips. It is.

[0003] Window frame rubber is manufactured from the viewpoints of productivity, wearability, design, etc., with the straight part as an extruded part and the corner part as a molded part. Normally, as shown in FIG. 1, after the extruded portions 1 and 1 obtained by cutting into a predetermined length are set in a molding die 11, a molding material is injected into a cavity 13 formed by the set and cured ( Vulcanization), and is manufactured by a method of integrally connecting the molded part 3 to the extruded part 1. Here, as the molding material, usually, ethylene propylene rubber, NBR / PVC polyblend, chloroprene rubber or the like is suitably used. The molding method is transfer or injection.

[0004]

In molding the above-mentioned molding part 3, the injection material does not flow into the extrusion molding part 1 side from the molding part side so that burrs (post-finishing process is troublesome) are not generated. In the case where the extruded portions 1 and 1 are set in the mold 11, the extruded portion 1 is tightly fitted (minus tolerance, usually h =
The cross-sectional size of the cavity 13 of the mold 11 is set so as to be 0.2 to 0.4 mm).

For this reason, after the molding is completed, when the mold is released, elastic return in the cross-sectional direction generally occurs in the extruded portion. Therefore, a step is likely to occur at the boundary between the molded part 1 and the extruded part 3. Also, a step occurs due to variations in the cross-sectional dimensions of the extruded part. When these steps occur in the design surface portion D, they degrade the design properties and are not desirable.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a weather strip which does not have a noticeable step at a boundary between a design portion and an extruded portion of a weather strip.

[0007]

The method of manufacturing a weather strip according to the present invention solves the above-mentioned problems by the following constitution.

In manufacturing a weather strip in which an extruded part and a molded part are integrally connected, an extruded part obtained by cutting an extruded product into a predetermined length is set in a molding die, and then the set is performed. In a method of injecting and curing a molding material into a cavity to be formed, and integrally connecting the molded part to the extruded part, the extruded part is formed by connecting the extruded part from the non-design surface part side to the design surface part side. It is characterized by being cut so as to be long and set in a molding die.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments (see FIGS. 2 and 3). The same parts as those in the above-described example are denoted by the same reference numerals, and all or part of the description thereof is omitted.

In the same manner as in the above example, the extruded part 1 obtained by cutting to a predetermined length is set in a molding die 11, and a molding material is injected and cured into a cavity 13 formed by the set. The window frame rubber (weather strip) is manufactured by a method of integrally connecting 3 to the extruded portion 1.

In this embodiment, in the above-described manufacturing method, the extruded portion 1 is cut so that the connecting end surface 2A is longer on the design surface D side from the non-design surface portion side, and the molding die 11 is formed.
Set to. At this time, the mode of the cutting may be a slope shape or the like, but is usually a straight oblique cutting. The cutting angle depends on the injection pressure (usually 980 to 1 for transfer).
372 Pa (100 to 140 kg / cm ² )), which varies depending on the fluidity of the molding material, the wall thickness at the design surface, and the like.
The intersection angle α with the axis is 40 to 70 °. If the angle is too large, the effect of the present invention is hardly achieved.

At this time, the minus tolerance of the interference fit of the extruded portion 1 with respect to the mold cavity 13 is the same as the conventional one.

When the extruded portion 1 is set in the molding die 11 and the molding material is injected into the cavity 11 to be formed, the molding material is tightly fitted. No burrs will flow out to the side.

When the mold is opened after the material has been cured (vulcanized), the elastic return of the extruded portion 1 occurs as in the prior art. At this time, since the connection end surface 2A of the extruded portion 1 is cut so as to be longer from the non-designed surface portion side to the designed surface portion D side, the thickness of the extruded portion 1 toward the design surface portion D side is increased. Is gradually decreasing. Therefore, the elastic return on the design surface portion D side is smaller than that on the non-design surface portion side. That is, a noticeable step occurs only on the non-design surface portion side. Therefore, there is no noticeable step in the design surface portion D of the weather strip.

The manufacturing method of the present invention is similarly applied to a glass run having an extruded portion 1A having a cross section as shown in FIG. 4 and a door weather strip having an extruded portion 1B having a cross section as shown in FIG. The extruded portions 1A and 1B can be applied by cutting them so that their connection end faces become longer from the non-design surface portion side toward the design surface portion D side, and set them in a molding die.

[0016]

According to the method for producing a weather strip of the present invention, as described above, an extruded part obtained by cutting an extruded product into a predetermined length is set in a molding die and then formed by the set. Inject molding material into the cavity
In the method of integrally connecting the molded part to the extruded part, the extruded part is cut so that the connection end face becomes longer from the non-design surface part side to the design surface part D side, and a molding die. Therefore, the following operations and effects can be obtained.

When the extruded part is set in a molding die, a molding material is injected into the formed cavity, and after molding, the mold is opened, the elastic return of the extruded part occurs as in the conventional case. However, on the design surface side, the return amount is small,
No noticeable step occurs.

The reason is that the connection end face 2A of the extruded part 1
However, since the length of the extruded portion 1 is gradually reduced toward the design surface portion D because the cut portion is cut so as to become longer from the non-design surface portion side to the design surface portion D side, the design surface portion D The elastic return on the side is smaller than that on the non-design surface part side.

Therefore, it is possible to provide a weather strip having a good design without a noticeable connection step between the extruded part and the molded part.

Furthermore, since the extruded part and the molded part are formed with the diagonally cut surface as the connection end face, tapered bonding is achieved, and the additional effect of increasing the bonding strength is also exhibited.

Although the invention of the present invention is not affected at all, Japanese Patent Application Laid-Open No. 3-87 discloses a method of manufacturing a weather strip of the present invention and a related prior art for achieving the same object.
No. 226 publication is available.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a mold after a molded portion is formed, showing a conventional method of manufacturing a weather strip.

FIG. 2 is a schematic cross-sectional view of a main part of a mold at the time of setting an extruded part when the method of the present invention is applied to a window frame rubber.

FIG. 3 is a schematic sectional view taken along line III-III in FIG. 2;

FIG. 4 is an end view showing a design surface portion of a glass run to which the manufacturing method of the present invention can be applied.

FIG. 5 is an end view showing a design surface portion of the door weather strip.

[Explanation of symbols]

 1, 1A, 1B Extruded part 2, 2A Connection end face 3 Mold part 11 Mold for molding 13 Cavity D Design surface part

Continuation of the front page (56) References JP-A-6-190861 (JP, A) JP-A-6-47839 (JP, A) JP-A-64-52548 (JP, A) JP-A-63-295215 (JP) JP-A-55-30981 (JP, A) JP-A-54-101877 (JP, A) JP-A-3-87226 (JP, A) JP-A-59-75015 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 45/00-45/17

Claims (1)

(57) [Claims] When manufacturing a weather strip in which an extruded part and a molded part are integrally connected, an extruded part obtained by cutting an extruded product into a predetermined length is set in a molding die. In a method of injecting and curing a molding material into a cavity formed by the set and integrally connecting a molded part to the extrusion part, the extruded part is connected to a design surface part from a non-design surface part side. A method for manufacturing a weather strip, comprising cutting the mold so as to be longer toward a side and setting the cut in the molding die.