JPH0311615B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a weather strip that is attached to the windows of automobiles and the like to prevent rainwater from entering. The present invention relates to a method of manufacturing a weather strip having a weather strip.

[Prior Art] For example, in a weather strip, in order to prevent rainwater that has flowed between the weather strip and the car body from entering the inside of the car, the lower side of the weather strip is generally used. A through hole is formed in the. In addition, the through hole that flows between the weather strip and the body is reliably discharged to the outside of the vehicle (see Japanese Utility Model Publication No. 54-40570).

A conventional method for manufacturing a weather strip having a through hole for draining water is as shown in FIG. 102,
The bottom part 103 was integrally molded using a mold, and as a post-processing, the bottom part 103 was removed using a jig such as a punching press, thereby forming the recess 101 into a through hole.

The reason for forming the bottom portion 103 is as follows. That is, in the case of a method for manufacturing plastic products, there is no particular need for something corresponding to the bottom part 103, but in the case of a method for manufacturing rubber weather strips, the mold is heated to a considerably high vulcanization temperature. Due to the heating, the amount of thermal expansion is greater than that of plastic molds, and unvulcanized rubber has extremely high fluidity. Therefore, the mold 100a of the mold 100 and the pin part 100c of the mold 100b shown in FIG. Even if rubber is injected, thin burrs are likely to occur between the mold surface of the mold 100a and the tip end surface of the pin portion 100c. Therefore, in the manufacturing method of the weather strip, if the occurrence of burrs is unavoidable, the bottom part 103 is intentionally formed to avoid contact between the pin part 100c and the mold 100a to prevent damage to the pin part 100c. I was thinking about it.

[Problems to be Solved by the Invention] In the manufacturing method described above, when removing the bottom part, if the bottom part is thin like a burr, it tends to stretch due to the rubber elasticity of the material. There was a problem in that unless it was supported from the reverse side, the cutting blade would act to stretch the bottom without cutting it, making it impossible to remove the bottom properly.

Further, the bottom of the recess is located on the bottom side of the weather strip, and this combined with the fact that the recess is curved makes it difficult to set it on the jig. For example, when cutting the bottom using a punching press, there was a problem in that even if a cut was made around the bottom, the cut material remained in the recess and did not form a through hole and did not drain water.

SUMMARY OF THE INVENTION The present invention provides a method for manufacturing a weather strip having a through hole for draining water, the bottom of which can be easily removed.

[Means for Solving the Problems] The method of manufacturing a weather strip having a through hole for draining water according to the present invention includes a recessed portion having an opening at one end, one end surface forming the bottom of the recessed portion, and the other end forming a recessed portion having an opening at one end. a first step of integrally molding a rubber molded body with a thick protrusion that protrudes to the opposite side of the opening and is connected to the periphery of the recess via a thin wall portion; The method is characterized in that the second step is carried out in sequence by grasping the thick protrusion of the rubber molded body, tearing it apart at the thin wall part, and extracting the bottom of the recess to form a through hole for draining water.

In the first step, a rubber molded body having a concave portion with one end open, and a thick protrusion protruding from the opposite side of the concave portion and connected to the rubber molded body through a thin wall portion,
Molded integrally using a mold. It is preferable that the thick protrusion is connected to the periphery of the concave portion by a thin portion all around, but in special cases, it may be locally connected by a thin portion.

The reason why the protrusion is made thick is to concentrate the expansion of the rubber in the thin part, making it easier to tear off, and to make it easier to grasp.

The size and shape of the protrusion can be selected as appropriate depending on the type of weather strip, but it should be thicker than the thin part, and the protrusion should be large enough to be grasped with the tips of your fingers. is preferred. It is also preferable that the protrusion has a mold-cutting slope formed on its outer surface so that it can be easily punched out from the mold. In addition, in order to reduce the amount of wasted material, the protrusion can be made to have a size and shape that can be used for other rubber parts. The thickness of the thin portion is appropriately selected depending on the properties of the rubber, its green formability, etc., but is generally about 0.05 to 0.5 mm, preferably about 0.2 mm.
If the thickness of the thin part becomes thick, there is a risk that the rubber molded body and the meat will be torn off when it is torn in the second step, so it is necessary to take this situation into account when setting the thickness of the thin part. The thickness of the thin portion may be uniform, or may be uneven with some variation in thickness. For example, in order to make the thin portion easier to tear, a notch groove or the like may be partially formed in the thin portion.

In the second step, the protrusion and the rubber molded body are separated by pulling one side of the rubber molded body against the other and tearing off the thin walled part, and the bottom of the recess is extracted to form the through hole. shall be. By tearing at the thin wall portion in this way, the protrusion can be separated without leaving any small pieces of meat left behind. The second step is usually carried out by fixing the rubber molded body through a filter and manually pulling the thick protrusions. In some cases, this may be reversed. The thin portion may be torn off by pinching the protrusion with fingertips and pulling the protrusion, or may be carried out by pulling the protrusion using pliers, pliers, or the like. If there is no particular problem during mold cutting, it is also possible to form minute irregularities on the surface of the protrusion when molding the protrusion, such as flat knurling, to make it easier to grasp with fingertips, etc. preferable.

The second step is generally carried out after the rubber molded article is released from the mold, but in some cases it is carried out when the mold is opened. It's okay. In this case, if the rubber molded body is attached to one side of the mold and the protrusion is attached to the other side of the mold, the thin part can be torn off using the opening force of the mold. Note that the protrusion attached to the other mold may be released using an extrusion pin.

[Effects of the Invention] According to the manufacturing method of the present invention, a through hole for draining water can be easily formed in the weather strip by tearing off the thin wall portion.

In the second process, if you grab the thick protrusion with your fingertips and tear off the thin part, there will be less dust when removing the bottom, compared to the conventional method where the bottom was removed using a special jig. It is preferable from an environmental hygiene point of view.

[Example] Originally, a rubber molded body having a concave portion is called a weatherstrip body, and one in which the concave portion becomes a through hole is called a weatherstrip. First, for convenience of explanation, the outline of the weather strip will be explained. FIG. 6 is a diagram showing the main parts of the weather strip. The weather strip consists of a base 10 and lips 11 and 12 integrally formed on the base 10.
and seal lips 13 to 15. Here, between the lip 11 and the base 10 is a groove 16 into which a part of the body is fitted, and between the lip 12 and the base 10 is a groove 17 into which a part of the glass is fitted. A through hole 18, which is used as a drainage hole, is formed through the weather strip. This through hole 18
This is to ensure that rainwater that has entered the gap between the body and the weather strip is drained out of the vehicle when the weather strip is attached to the window of the body.

Next, a method for manufacturing the weather strip described above will be explained. 2 to 4 show the mold 2 used in the first step of this embodiment. The mold 2 is
Dies 20 to 23 are cut in different directions.
The configuration has the following. This mold 2 is mold 20-2
3 has a cavity 24 corresponding to the corner of the weather strip. As shown in FIG. 2, the mold 22 has a pin portion 25 corresponding to the through hole 18 serving as the water drainage hole. This pin portion 25 forms a part of the mold 2. The mold 23 has a protrusion cavity 26 at a position facing the pin part 25. A slight gap 27 is provided between the mold surface of the mold 23 and the pin portion 25.

In the first step, although not shown, the right side of the weather strip, which has been previously manufactured by extrusion molding, is set at a predetermined portion of the mold 2. Then, rubber adjusted to a predetermined composition is injected into the cavity 24 of the mold 2 having the above-described configuration, and the inside of the cavity 24 is filled with the rubber. At this time, gap 2
7. The cavity 26 for the protrusion is also filled with rubber. After that, the mold 2 is opened. Then, a weather strip main body is obtained in which the corner portion 4 whose cross section is shown in FIG. 1 and the above-mentioned right side portion are joined. The reason why the corner portion 4 and the right side portion are manufactured separately is that the right side portion can be manufactured at a lower cost if it is formed by extrusion molding and then cut. As shown in FIG. 1, the corner 4 of the weather strip main body formed in this manner includes a corner main body 42 having a recess 40 with one end 40a open, and a thin wall portion protruding to the opposite side of the recess 40. It is composed of a thick protrusion 5 connected by 41. FIG. 5 is a perspective view mainly showing the protrusion 5. FIG.

Here, the protrusion 5 is formed by filling a protrusion cavity 26 with rubber, and the protrusion 5 is formed by filling the protrusion cavity 26 with rubber.
0 corresponds to the pin part 25, and the thin part 4
1 is formed by rubber flowing into the gap 27. Note that the reason why the protrusion 5 is made thick is that the elasticity of the rubber is concentrated in the thin part 41.
This is to make it easier to tear off in the second step and to make it easier to grasp.

In the second step, the protrusion 5 is held and pulled with a fingertip or the like. Then, since the protruding portion 5 is thick, the force that causes the rubber to stretch is concentrated on the thin portion 41.
1, it is torn off from the corner main body 42, and the protrusion 5 and the corner main body 42 are separated. As a result, the recess 4
0 is in the penetrating state, and the through hole 18 as a drainage hole
become.

7 to 10 show a second embodiment of the present invention. The second embodiment shows an example in which the present invention is applied to a roof weather strip of an automobile. FIG. 7 shows the opening 74.
Fig. 8 is a perspective view of the end of the roof weather strip main body 7 made of rubber, which includes an insert panel 74 with a built-in insert panel 74, viewed from the front side; is a diagram,
FIG. 9 is a sectional view of a state in which the thick protrusion 8 and the roof weather strip main body 7 are integrally molded with a thin wall portion 71 interposed therebetween.

Also in this second embodiment, in the first step, the roof weather strip main body 7 having a recess 70 with one end open is connected to the roof weather strip main body 7 by a thin wall portion 71 that protrudes on the opposite side of the recess 70. The thick protrusion 8 thus formed is integrally molded using a mold. In addition, the thickness of the thin part 71 is 0.1~
It was set to about 0.2 mm.

In the first step, as shown in FIG. 10, the pin portion 83 of the hollow core 82 for forming the recess 70 is fitted into the recess 81a of a mold 81 having a cavity 80 for a projection corresponding to the projection 8. In addition, other molds (not shown) can also be used.

In the second step, by pulling the thick protrusion 8 with your fingertips and tearing it off with the thin part 71,
The protrusion 8 and the roof weather strip main body 7 are separated, thereby making the recess 70 a through hole, thereby producing a roof weather strip having a through hole. Incidentally, FIG. 11 shows a view corresponding to FIG. 9 of the conventional example, and the burr-shaped bottom 72 protruding into the recess 70 had to be removed with scissors or the like.

[Brief explanation of the drawing]

1 to 6 show a first embodiment of the present invention,
FIG. 1 is a sectional view of a corner of a weather strip main body that integrally has a thick protrusion through a thin wall;
Figure 2 is a sectional view of the mold, Figure 3 is a front view of the mold, Figure 4 is a sectional view taken along the - line, Figure 5 is a perspective view of the main parts of the weatherstrip body near the protrusion, FIG. 6 is a perspective view of the weather strip near the through hole. 7 to 10 show a second embodiment of the present invention, FIG. 7 is a perspective view of the main parts of the roof weather strip main body as seen from the surface side, and FIG. 8 is a perspective view of the main part of the roof weather strip. FIG. 9 is a perspective view of the main body viewed from the back side, FIG. 9 is a sectional view of the main part, and FIG. 10 is a perspective view of the main part of the mold for forming the protrusion. FIG. 11 is a sectional view of a conventional roof weather strip main body before the bottom portion is removed. FIG. 12A is a cross-sectional view of a conventional weather strip main body before the bottom portion is removed, and FIG. 12B is a cross-sectional view of the main part of the mold. In the figure, 2 is a mold, 4 is a corner, 40a is one end,
40 is a concave portion, 41 is a thin wall portion, 42 is a corner body (rubber product body), 5 is a protrusion, 18 is a through hole, 7 is a roof weather strip body (rubber molded body),
70 is a recessed portion, 71 is a thin walled portion, and 8 is a protrusion.

Claims (1)

[Scope of Claims] 1. A recessed portion having an opening at one end, one end surface forming the bottom of the recessed surface, the other end protruding to the side opposite to the opening, and connected to the periphery of the recessed portion via a thin wall portion. a first step of integrally molding a rubber molded body having a thick protrusion by molding; grasping the thick protrusion of the rubber molding and tearing it off at the thin wall part; A method for manufacturing a weather strip having a through hole for draining water, characterized in that a second step of separating the weather strips and extracting the bottom part of the recess to form a through hole for draining water is carried out in sequence. 2. The method of manufacturing a weather strip having a through hole for draining water as claimed in claim 1, wherein the thin wall portion is completely encircled around the thick protrusion. 3. The thick protrusion has a size that can be grasped with a fingertip, and the second step is performed by manually tearing off the thick protrusion at a thin portion. A method for manufacturing a weather strip having through holes for water drainage.