JPH0261368B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an injection mold for automotive weather strips.

2. Description of the Related Art Conventionally, weather strips used for front and rear windows of automobiles, as shown in FIG. 1, consist of a straight section that is an extrusion molded product and a corner section that is an injection molded product that is connected to the straight section. That is, this weatherstrip 1 is constructed such that a weatherstrip component 2 on a straight portion and a weatherstrip component 3 on a corner portion are integrally connected at a joint surface 4.

By the way, the weather strip structure 2 of the linear portion is usually connected to a welt 7 having a sealing lip 5 at one end and a U-shaped cross section having a plurality of retaining lips 6 on the inner surface, and the other end of this welt 7. It is composed of a solid rubber base consisting of a panel seal lip 8 having a dogleg shape in cross section, and a glass seal lip 9 having a dogleg shape in cross section and made of sponge rubber. On the other hand, in order to improve molding efficiency, the welt 10, panel seal lip 11, glass seal lip 12, etc. of the weather strip structure 3 at the corner are molded from a single material of sponge rubber or solid rubber. It is integrally bonded to the weather strip structure 2 by injection molding.

However, when the weather strip component 3 is made of sponge rubber, the difference in level at the joint surface 4 can be reduced compared to when it is made of solid rubber, but the vulcanization time is longer, the cost is higher, and the appearance is poorer. Also, while forming the product with solid rubber is cheaper and has a nicer appearance, the glass seal lip 9 that was pressed at the joint during injection molding stretches and creates a step at the joint. There was a problem in that the glass seal lips 9 and 12 hit the glass surface unevenly, resulting in water leakage.

In contrast, sponge rubber is interposed only on the joint surface of the glass seal lip, and a weather strip component at the corner portion made of solid rubber is injected into the weather strip component at the straight portion. A weather strip can be considered in which the two components are integrally joined by foaming and vulcanizing the sponge rubber, thereby preventing the formation of a step between the glass seal lips of the two components. Conceivable.

However, the sponge rubber to be interposed is elastic in itself, and when the solid rubber fabric of the weather strip component at the corner portion is injected, the sponge rubber is crushed by the injection pressure and has already been extruded. In some cases, the sponge rubber was not molded so as to smoothly join the glass seal lips of both weatherstrip structures.

The present invention has been made in view of the above-mentioned problems in the prior art. A space is formed surrounding the sponge rubber interposed on the seal lip joint surface, and a rib is integrally provided to restrict the flow of the solid rubber material into that space during injection molding. The glass seal lips of both weather strip components are connected smoothly without any steps by foaming and vulcanizing the sponge rubber to prevent displacement of the sponge rubber due to injection pressure. The present invention provides an injection mold for weather strips.

FIGS. 2 and 3 specifically show the injection molding mold of the present invention. In the same figure, 21
is an injection molding mold, in which the straight part of the weather strip structure 2 already configured as an extrusion molded product is held at a predetermined angle, and inside a cavity 22 corresponding to a corner part of the injection molding mold. So-called joint molding is performed by injecting solid rubber.

This cavity 22 consists of a seal lip part 23, a holding lip part 24, a welt part 25, a panel seal lip 26, and a glass seal lip part 27 having a dogleg shape in cross section. It faces the end face of the structure 2. Further, a core metal 28 is held within the welt portion 25.

Further, the glass seal lip portion 27 is provided with a recess 29 adjacent to the joint surface 4 of the glass seal lip 9 of each weather strip structure 2.

In order to form the cavity 22, the injection mold 21 includes an upper mold 30, a lower mold 31, and a plurality of plate-shaped core molds 32, 33, 34, 35 arranged between the upper and lower parts 30, 31. It consists of
The tip of the core mold 32 is connected to the glass seal lip portion 2.
7, a part of the rib 36 protrudes in a T-shape. The edge of this rib 36 extends near the middle of the glass seal lip portion 27, and the solid rubber fabric into which a portion of the rib 36 is injected is held by the rib 36 on the glass seal lip 9 side of the weather strip structure 2. The flow is now being restricted. In addition, the rib 36 and the glass seal lip 9
A space 38 in which sponge rubber is interposed is provided in between. In addition, 37 is the injection hole of the solid rubber fabric,
This communicates with the panel seal lip 26 of the cavity 22.

According to the mold 21 having such a structure, first, the straight portion of the weather strip structure 2 is held as described above, and a sponge is inserted into the space 38 of the T-shaped rib 36 on the glass seal lip 9 side. rubber fabric 3
9, and then inject the solid rubber fabric through the injection hole 37. The injected solid rubber fabric is placed in cavity 2 as shown by the dashed line in Figure 2.
However, the presence of the ribs 36 restricts the solid rubber material from flowing into the space 38 in which the sponge rubber material 39 is placed. At this point, the injection of the solid rubber is stopped, vulcanization is performed, and the sponge rubber material 39 is foamed and vulcanized. Therefore, the sponge rubber fabric 39 is not directly affected by the injection pressure of the solid rubber fabric 39, but expands to fill the space, and due to residual heat, the foamed sponge rubber is integrally connected with the injected and molded solid rubber, making it continuous. The desired weather strip can be obtained. As a result, the sponge rubber is in the correct position and smoothly connects the glass seal lips of each weatherstrip assembly.

As explained above, according to the present invention, injection molding is applied to the weather strip structure of the straight part which integrally has a solid rubber base and the glass seal lip made of sponge rubber, and to the weather strip structure of the corner part. In an injection molding mold for an automotive weather strip comprising an upper mold, a lower mold, and a core mold inserted between these two molds, the glass in either the upper mold, the lower mold or the core mold is By forming a space near the end of the seal lip for inserting the sponge rubber fabric and integrally providing a rib that restricts the inflow of the solid rubber fabric into the space, it is possible to prevent weather in the straight portion. The sponge rubber fabric can be precisely positioned near the glass seal lip of the strip component, and the sponge rubber smoothly connects the glass seal lips of both weather strip components without any steps. It is possible to significantly improve the sealing performance against the glass at the corner portion and the joint portion of the straight portion.

[Brief explanation of drawings]

FIG. 1 is a front view of a conventional weatherstrip clearly showing the end face of the weatherstrip, and FIG. 2 is a front view of a weatherstrip structure of the straight portion held in the mold of the present invention. FIG. 3 is a sectional view of the mold structure. DESCRIPTION OF SYMBOLS 1...Weather strip, 2...Weather strip structure in a straight part, 3...Weather strip structure in a corner part, 4...Joint surface, 9...
...Glass seal lip, 21...Mold, 22...
Cavity, 36...Rib, 37...Injection hole, 3
8... Space, 39... Sponge rubber fabric.

Claims (1)

[Claims] 1 An upper mold, a lower mold, and the like are used to injection mold a corner weather strip structure into a linear weather strip structure that integrally has a solid rubber base and a glass seal lip made of sponge rubber. In an injection molding mold for an automotive weather strip consisting of a core mold inserted between both molds, sponge rubber is placed near the end of the glass seal lip of either the upper mold, the lower mold, or the core mold. An injection mold for an automobile weather strip, characterized in that a rib is integrally provided to form a space in which the fabric is interposed and to restrict the inflow of the solid rubber fabric to be injected into the space.