JPH06210764A - Molding of weather strip - Google Patents

Abstract

PURPOSE:To mold a weather strip so that no burr generates in the split surface of a mold. CONSTITUTION:A mold 3 used for the important molding part of a weather strip in a cavity 5, for example, a slit surface 4 which comes in contact with a part where a seal lip 22 is molded, has a tunnel-type groove 6a running along the cavity 5 with a small space left to the cavity 5. Further, the cavity 5 and the groove 6a are filled with a solid rubber by injecting the solid rubber into the cavity 5, and a weather strip molded in the cavity 5 is taken out by tearing it off the solid rubber 2a which is allowed to remain in the groove 6a to perform a first molding process. In addition, a second and following molding processes are performed in such a state that the solid rubber 2a continues to remain in the groove 6a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a weather strip, and more particularly to a method for molding a weather strip made of solid rubber.

[0002]

2. Description of the Related Art Taking a weather strip (commonly called a glass run) attached to a door sash of an automobile door as an example, a weather strip 2 is attached along the inside of a door sash 1 as shown in FIG. It plays a role of guiding up and down and sealing the outer periphery when the door glass is closed.

As shown in FIG. 4, the weather strip 2 has a basic structure in which seal lips 22 and 23 sandwiching the peripheral edge portion of the door glass extend from both ends on the opening side of a base portion 21 having a U-shaped cross section. Note that, as shown in the figure, there is also one provided with a lip 24 that wraps the inner side wall of the door sash 1 from the opening end that is the inside of the vehicle when attached to the door sash 1.

The weather strip 2 is obtained by connecting extruded products 2A, 2B and 2C made of solid rubber into a corner shape at a corner by molding.

When the die-molding connection portions 2D and 2E are molded by a die, burrs are generated on the divided surface of the die which is in contact with the outer periphery thereof. This burr is thin and extends irregularly from the outer surface of the molding connection, especially the seal lip 2 on the outside of the vehicle.
If such a burr is generated at the tip of No. 2, not only the appearance is impaired, but also the sealing property with the outer surface of the door glass is deteriorated, which is not preferable.

Therefore, although the burrs are removed after molding, it is extremely troublesome to manually remove the thin burrs. Therefore, in order to improve the workability of burr removal, FIG.
The measures shown in are taken. That is, a mold 3 is used in which a dividing surface 4 of the cavity 5 that is in contact with the molding portion of the seal lip 22 is formed with a tunnel-shaped groove 6c which is close to the cavity 5 and is generally called a hand-cut groove along the divided surface 4. Then, a slight excess of solid rubber is injected into the cavity 5 and the rubber is positively introduced into the groove 6c to generate a burr having a thick tip edge, and the thick tip edge is manually pinched to tear the burr.

However, in this means, the groove 6
When c is completely filled with rubber, extra rubber material is consumed for each molding. In addition, if the injection is incomplete, the injection pressure in the cavity 5 will be insufficient,
There is a possibility that the pressure contact force at the connection interface between the die-molded portion and the end of the extrusion-molded body connected thereto is insufficient and connection may be lost.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and it reduces waste of rubber material and eliminates the need for deburring work on the outer surface of a weatherstrip for molding. The object of the present invention is to provide a method for molding the strip.

[0009]

According to the molding method of the present invention,
As shown in FIG. 1, weather strip mold forming portions 2D, 2
A tunnel-shaped groove 6a is formed on the dividing surface 4 of the mold 3 for molding E (FIG. 3) along the cavity 5 with a small space. The groove 6a has a structure in which the rubber material filled therein does not come off together with the product when the product is taken out. For example, as shown in FIG. 1C, the groove 6a has an undercut shape. Alternatively, as shown in FIG. 2B, the rod member 7 is inserted into the groove 6b.
The tip of the is projected to prevent the rubber in the groove 6b from coming off.

Then, solid rubber is injected into the cavity 5 of the mold having the groove 6a (or 6b),
The groove 6a is filled together with the cavity 5.

After molding the die-molded portion 2D of the weather strip in this manner, the die-molded portion 2D is taken out while being broken from the solid rubber in the groove 6a to obtain the first product.

After the second time, the solid rubber is retained in the groove 6a, and the solid rubber is injected into the cavity 5 to successively manufacture the products.

[0013]

After the second time, since the groove 6a is already filled with rubber to seal the division 4, solid rubber is injected into the cavity 5 for molding, and the product is taken out similarly to the first time. Is obtained.

If the molding is repeated for a long time, the rubber in the groove 6a deteriorates due to the high temperature. When the deterioration occurs, the rubber is removed from the groove 6a, and the molding is performed by the above-described first method.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first embodiment in which the present invention is applied to the molding of a corner molding portion 2D of the weather strip 2 shown in FIG.

Extruded weather strips 2A, 2B
As shown in FIG. 1A, the mold for molding the mold molding portion 2D for connecting (FIG. 3) includes an upper mold 3A, a lower mold 3B, a middle mold 3C,
3D, 3E, 3F, with a cavity 5 between them
Are formed. The cavity 5 is substantially the same as the extrusion-molded weather strips 2A and 2B made of solid rubber having a U-shaped base 21 shown in FIG. 1B and seal lips 22 and 23 extending from both ends of the opening. Have the same cross-sectional shape.

A tunnel-shaped groove 6a is formed on the dividing surface 4 between the lower mold 3B and the middle mold 3D along the tip of the molding portion of the seal lip 22 of the cavity 5 with a slight gap. As shown in FIG. 1C, the groove 6a has an undercut shape on the lower die 3B side.

In order to mold the mold molding portion 2D with the mold 3 having the above structure, first, FIG. 1B (the upper surface of the lower mold 3B is shown).
As shown in (3), the ends of the weather strips 2A and 2B formed by extrusion are inserted into both ends of the cavity 5, and the mold 3 is closed.
Next, press the solid rubber into the cavity 5 and press it, as shown in FIG.
As shown in FIG. 5, the solid rubber is filled in the groove 6a together with the cavity 5.

After the rubber is vulcanized, the upper mold 3A is raised,
The middle mold 3C is slid, and the middle molds 3D, 3E, 3F are rotated around the hinges 31, 32 to open the mold. Then, the mold molding portion 2D molded in the cavity 5 and connecting the weather strips 2A and 2B is taken out from the lower mold 3B. At this time, since the rubber 2a in the groove 6a does not come off, the mold forming portion 2D
Is broken and taken out from the rubber 2a. Although thin and minute protrusions remain linearly at the tip of the seal lip 22 of the molded portion 2D that has been taken out, this does not impair the appearance and the sealing performance with the door glass.

In the second and subsequent moldings, the rubber 2a is placed in the groove 6a.
Is retained and held, the solid rubber is filled only in the cavity 5 and the product is taken out.

FIG. 2 shows a second embodiment of the present invention. The difference from the first embodiment is the groove structure of the die used.

That is, along the dividing line 4 and the cavity 5
Both ends 61, 61 of the tunnel-shaped groove 6b along the tip of the molded portion of the seal lip 22 are deeply formed on the lower mold 3B side. The tip ends of the rods 7, 7 fitted in the lower mold 3B along the dividing surface 4 are projected at both ends 61, 61. The other mold structures are the same as in the first embodiment.

When this mold is used, the cavity 5 and the groove 6b are filled with solid rubber and molded, and the mold molding portion 2
When D is taken out, the rubber 2a in the groove 6b is prevented from coming off by the rod member 7. The removal of the first product and the molding of the second and subsequent products are the same as in the first embodiment.

The mold used in the second embodiment is the groove 6
The processing of b and the processing for attaching the rod member 7 are the first
This is advantageous in that it is simpler than the processing of the undercut groove 6a in the above embodiment.

[0025]

According to the present invention, it is possible to mold a weather strip having no burrs on the surface that would impair the appearance and sealability. Therefore, deburring work after molding is unnecessary.

Further, since the surplus rubber material other than the product portion is consumed only in the first molding, there is almost no waste of the rubber material. Further, since the groove is filled and held with solid rubber, the molding material does not escape into the groove, and sufficient pressure is applied to the connection interface between the extrusion section and the molding section to improve the connection strength.

The present invention can be widely applied not only to a weather strip (glass run) attached to a door sash, but also to other weather strips molded with solid rubber.

[Brief description of drawings]

FIG. 1 (A) is a cross-sectional view of a mold for molding a mold forming portion of a weather strip by the method of the present invention, and FIG. 1 (B) is viewed from above a cavity of a lower mold during molding. FIG. 1 (C) is a cross-sectional view of the rubber injection state at a position along the IC-IC line in FIG. 1 (B).

FIG. 2 (A) is a view corresponding to FIG. 1 (B) of a mold for molding a mold forming portion of a weather strip by another method of the present invention, and FIG. 2 (B) is shown in FIG. 2 (A). FIG. 11B is a sectional view of the rubber injecting state at a position along the line IIB-IIB in FIG.

FIG. 3 is a view showing a weather strip to which the present invention is applied.

4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a sectional view of a conventionally used mold corresponding to FIG. 1 (C).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Door sash 2 Weather strip 2A, 2B, 2C Extrusion molding member 2D, 2E Mold molding part 22,23 Seal lip 3 Mold 3A, 3B, 3C, 3D, 3E Mold member 4 Dividing surface 5 Cavities 6a, 6b Groove 7 Bar member

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B60J 10/08 // B29K 21:00 105: 24 B29L 31:30 4F

Claims (1)

[Claims] 1. A tunnel-shaped groove is formed along the outer periphery of the cavity at a slight interval on a divided surface of a die having a cavity for molding a weather strip, and a solid is formed in the cavity of the die in which the groove is formed. Inject rubber to fill the cavities and grooves to form a weather strip, and with the solid rubber in the groove remaining, rupture the weather strip formed in the cavity from the solid rubber in the groove and take it out. Thus, the method for forming a weather strip is characterized in that the first molding is carried out and the second and subsequent moldings are carried out in a state where the solid rubber is continuously retained in the groove.