JP3105453B2 - Weather strip and its molding die - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weather strip in which a molded part is connected to an end of an extruded member having a hollow portion, such as a door weather strip of an automobile, and a molded metal used in the case. About the type.

[0002]

2. Description of the Related Art In general, at a terminal portion or a corner portion of a weather strip such as a door weather strip of an automobile, a molding portion is formed so as to be connected to a terminal of an extruded member extruded into the same cross-sectional shape using a rubber material. Are molded. A molding die for molding the molded part is formed by laminating a plurality of plate members to form a cavity having substantially the same shape as the molded part. When the strip has a hollow portion, a core die is used in order to obtain a hollow cross-sectional shape also in the molded portion.

As an example, FIG. 6 shows a mold for forming a weatherstrip disclosed in Japanese Utility Model Laid-Open No. 3-103711. This mold has an upper die 1, a lower die 2, and a core die 5 that forms a hollow portion 4 of the molded part 3. The tip part (fitting portion) 5 a of the core die 5 is While being inserted into the hollow portion 7, an unvulcanized rubber material is injected into a cavity 8 formed between the upper die 1 and the lower die 2 and vulcanized, so that a die continuous with the extrusion member 6 is formed. The forming part 3 is formed. The symbol L indicates a connection surface between the extrusion member 6 and the molded portion 3. Here, in order to prevent the extruded member 6 from escaping outward (to the left in the figure) due to the injection pressure of the unvulcanized rubber material, the concave / convex portions 9 for preventing the extruded member 6 from escaping are provided on the outer periphery of the fitting portion 5a. Is formed.

[0004]

However, when such uneven portions 9 are formed, compression marks may be left on the outer surface of the weather strip constituting the design surface, and the appearance quality may be degraded. In Japanese Utility Model Application Laid-Open No. 3-103711, the cross-sectional shape of the concave and convex portion 9 is set to a saw blade shape in order to suppress deformation due to compression. However, the inner surface of the extruded member 6 is still compressed locally. However, compression traces cannot be completely eliminated.

As shown in FIG. 6, if the thickness of the extruded member 6 is equal to that of the molded portion 3 with the connecting surface L interposed therebetween,
Since the distance between the outer surface of the core mold 5 forming the molded part 3 and the mold surface opposed thereto changes according to the thickness of the extruded member 6, the injection material is injected into the cavity 8. Thus, the surface pressure acting on the pushing member 6 becomes non-uniform. More specifically, the injection material easily flows into the portion having the large space, so that the surface pressure locally increases in this portion. As a result, there is a possibility that the extruded member 6 may escape or be turned up.

[0006] When the material of the extruded member and the injection material of the molded portion are different, for example, when the extruded member is sponge rubber and the injection material is solid rubber, the connection between the extruded member and the injection material is made. There is also a problem that the reaction force difference between the surfaces increases, and a connection step easily occurs on the connection surface L.

[0007]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a weather strip forming die for forming a molded portion so as to be connected to an end of an extruded extruded member having a hollow portion. A core mold that forms a hollow portion of the molding portion is provided, and the core mold includes a rod-shaped hollow molded portion, and a fitting portion that projects in a rod shape from an end surface of the hollow molded portion and fits into the hollow portion of the extrusion member. The distance between the outer surface of the hollow molded portion and the mold surface facing the hollow molded portion has a substantially constant width, and the outer surface of the hollow molded portion is stretched closer to the mold surface than the outer surface of the fitting portion. It is characterized by being put out.

At the time of molding, first, a core-shaped fitting portion is inserted into the hollow portion of the extrusion member until the end surface of the extrusion member and the end surface of the hollow molded portion abut against each other. Here, at the end surface of the hollow molded portion, which serves as a connection surface between the two, the outer surface of the hollow molded portion protrudes more toward the mold surface than the outer surface of the fitted portion, so that a step is formed between the hollow molded portion and the fitted portion. An attachment portion is formed so that the fitting position can be easily determined.

Next, the extruded member is set in a molding die, and a rubber material is injected to form a molded portion. Here, the outer surface of the hollow molded portion is made to protrude more toward the mold surface than the outer surface of the fitting portion, and the gap between the outer surface of the hollow molded portion and the mold surface facing the same is substantially constant. The flow of the material is constant, and the surface pressure of the injected material can be constant and relatively small. Therefore, in addition to being able to prevent the extrusion member from escaping or turning over,
There is no need to provide an uneven portion or the like for preventing the extruded member from escaping on the outer surface of the fitting portion, and the fitting portion can be formed in a bar shape. As a result, it is possible to completely eliminate the occurrence of the compression trace as in the related art described above.

In particular, in the present invention, the extruded member and the molded portion are made of different materials, for example, the extruded member is made of sponge rubber, and the molded portion is made of solid rubber. It is most effective when.

That is, a weather strip according to the present invention is a weather strip obtained by molding a molded portion so as to be connected to an end of an extruded extruded member having a hollow portion, wherein the extruded member is made of sponge rubber. On the other hand, the molded part is made of solid rubber, and the molded part is formed with a substantially constant width along the outer surface of the extruded member, with at least a thinner wall than the extruded member, with the connecting surface between them being sandwiched. It is characterized by:

[0012]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. 1 and 2 show a door weatherstrip provided on a front door of a sashless vehicle according to the present embodiment. The weather strip 10 is formed by molding a molding part 14 using the molding die of the present embodiment so as to be continuous with the end of the extrusion member 12. In addition, the code | symbol L has shown the joining surface of the extrusion member 12 and the molded part 14.

The extruding member 12 has a relatively large main hollow portion 16 serving as a seal portion, and two relatively small mounting hollow portions 18 and 20 which are isolated from each other by partition walls 22 and 24. . On the other hand, the molded part 14 includes an extended part 26 having substantially the same shape as the extruded member 12 and an attachment base 27 attached to the rear part of the door. Extension 2
6, one hollow portion 28 is formed, and this hollow portion 28 communicates with three hollow portions 16, 18, 20 of the extruded member.

The extruding member 12 is formed of sponge rubber so as to contact and seal the vehicle body when the door is closed. On the other hand, the molded portion 14 is in contact with the weather strip attached to the vehicle body side when the door is closed so as to be continuous with the weather strip, and can bleed out the oil to prevent generation of abnormal noise at the time of contact. It is formed from solid rubber. That is, if the molded part 14 is made of sponge rubber, it is necessary to perform a surface treatment after molding, but if the molded part is made of solid rubber as in this embodiment, the oil bleeds out. Since it is possible to do, there is no need to perform surface treatment after molding,
This surface treatment step can be omitted.

FIGS. 3 and 4 show a molding die 30 for molding the molded part 14. This mold 30 is used for the upper mold 3
2, a lower mold 34, and a slide mold 36 located therebetween.
And the core mold 4 forming the inner surface of the hollow portion 28 of the molded portion 14
And a cavity 41 having substantially the same shape as the molded portion 14 is defined by these components. The mold surface 32a of the upper mold 32 mainly forms the outer surface of the mounting base in the mold portion 14, and the mold surface 34a of the lower mold 34 and the mold surface 36a of the slide mold 36 mainly
The outer surface of the main hollow portion 16 is formed.

FIG. 5 shows only the core type 40. The core mold 40 is mainly composed of a solid rod-shaped hollow molded part 42 forming the inner surface of the hollow part 28 of the molded part 14, and a relatively thin wall extending substantially perpendicularly to the side of the hollow molded part 42. A core support 44 is provided. The rear side (the side opposite to the extrusion member) 46 of the hollow molded portion 42 has a shape curved toward the core support portion 44 so that the core mold 40 can be easily extracted from the product after molding.

The distal end surface 50 of the hollow molding portion 42 on the side where the extrusion member 12 is attached is provided with the main hollow portion 1 of the extrusion member 12.
6 and three rod-like fitting portions 52, 54, 56 which are press-fitted into the mounting-side hollow portions 18, 20 respectively. Note that the fitting portions 52, 54, and 56 are formed relatively long as the cross-sectional area increases, in order to obtain sufficient structural strength.

Here, the outer surface of the hollow molded portion 42 is larger than the entire outer surface of the fitting portions 52, 54, 56 in the mold surfaces 32a, 3a.
4a and 36a, and as shown in FIG. 3, the outer surface of the hollow molded portion 42 and the mold surface 32 facing the outer surface.
The distance H between the a, 34a, and 36a is substantially uniform over the entire circumference. That is, the hollow molded portion 42 is formed to have a substantially similar shape to the cross-sectional shape formed by the mold surfaces 32a, 34a, and 36a opposed thereto. As shown in FIG. 5, the fitting portions 52, 54, 56 protrude from the inside of the end surface 50 of the hollow forming portion 42, and the hollow forming portion 42 and the fitting portions 52, 54, 54, on the distal end surface 50 of the hollow forming portion 42.
A step 58 is formed between the step 56 and the step 56.

The fitting portions 52, 54, and 56 are solid rods having substantially the same cross-sectional shape as the hollow portions so that the inner surfaces of the hollow portions 16, 18, and 20 of the pushing member 12 are not locally compressed. Is formed. In other words, the fitting portions 52, 5
The outer surfaces of the four and 56 are not provided with any uneven portions that engage with the inner surface of the hollow portion of the pushing member 12.

Next, the molding die 3 configured as described above
The operation when molding the molded part 14 using 0 will be described. First, the hollow portions 16, 18, 18 of the terminal portion of the pushing member 12,
The fitting portions 52, 54, 56 of the core mold 40 are press-fitted into the inside 20, and are pushed until the end face 50 of the hollow molded part 42 comes into contact with the end face of the extruded member 12. Here, the fitting portions 52, 54,
Since no irregularities are provided on the outer surface of 56, the press-fitting operation is easy. Further, since the stepped portion 58 is provided on the end surface 50 of the hollow molded portion 42 that becomes the connection surface L, the insertion position can be easily determined.

Then, the core supporting portion 44 is sandwiched between the upper die 32 and the lower die 34, and the hollow molded portion 42 is set between the upper die 32 and the lower die 34 together with the extruding member 12.
Together with the mold. Next, a softened unvulcanized solid rubber material is injected into the cavity 41 and vulcanized to form the molded part 14, and the end face thereof is joined to the end face of the extruded member 12. The hollow molded part 4
2, the molded part 14 becomes hollow, and the core support part 44 forms a slit 38 on the side surface of the molded part 14 as shown in FIGS.

Here, since the fitting portions 52, 54, 56 are fitted into the hollow portions 16, 18, 20, respectively, the rubber material is prevented from flowing into the respective hollow portions.

In this embodiment, the hollow molded part 4
2 and the distance H between the mold surfaces 32a, 34a, 36a
Is relatively thin and has a substantially constant width, so that the flow of the injection material is constant, and the surface pressure of the injection material acting on the end face of the extrusion member 12 is also relatively small. That is, the surface pressure from a solid rubber material having a high rubber hardness can be reduced. As a result, escape and turning of the extruded member are prevented, no connection step is formed on the connection surface L, and adverse effects such as a difference in shrinkage due to a difference in material between the extruded member 12 and the injection material are caused. Can be minimized.

Further, by reducing the surface pressure acting on the end face of the push-out member 12, it is possible to provide a structure in which the concave and convex portions for preventing the push-out member 12 from escaping are not provided on the outer peripheral surfaces of the fitting portions 52, 54, 56. That is, the fitting portions 52, 54, 5
6 can be configured as solid bars each having the same cross-sectional shape. As a result, it is possible to completely prevent a trace of compression from being left on the outer surface of the weather strip after molding. In addition, since it is not necessary to perform a special molding process such as providing an uneven portion on the outer periphery of the fitting portion as in the related art, it is advantageous in terms of cost.

Since the molded part 14 is a solid rubber having a high rubber hardness, there is no problem in strength even if the molded part 14 is thinned to some extent. That is, the thickness of the interval H is set in consideration of the surface pressure of the injection member acting on the end face of the extrusion member and the strength of the molded portion 14 after molding.

After the vulcanization of the molding section 14 is completed, the mold is opened and the molded product is taken out. Here, no irregularities are provided on the outer surfaces of the fitting portions 52, 54, 56, so that it is not necessary to pull out the hollow molded portion 42.

In the weather strip 10 thus formed, as shown in FIG. 2, a molded portion 14 facing the connection surface L is formed with a substantially constant width along the outer surface of the extruded member 12. In addition, the molded part 14 is thinner than the extruded member 12. The outer surface of the weatherstrip 10 constituting the design surface has no compression marks or connection steps, and has excellent appearance quality. In addition, in order to maintain the strength as the weatherstrip attaching portion, a part of the attaching base portion of the molded portion 14 (the lower left portion in FIG. 2) is not thinned from the extruding member 12 and impairs the above-described effects. The thickness is slightly thicker than other portions of the molded part 14 to such an extent that no problem occurs.

[0028]

As described above, according to the present invention, the distance between the outer surface of the hollow mold portion of the core mold and the mold surface opposed thereto is set to a substantially constant width, and the outer surface of the hollow mold portion is extruded. The member protruded more toward the mold surface than the outer surface of the fitting portion fitted into the hollow portion of the member. Therefore, when the rubber material is injected into the cavity of the mold, the surface pressure of the injection material acting on the end surface of the extrusion member can be made constant and relatively small. Thereby, it is possible to reliably prevent the extrusion member from running away or being turned up, and from forming a step on the connection surface between the extrusion member and the molded portion.

Further, by reducing the surface pressure acting on the pushing member as described above, it is possible to form the fitting portion into a rod shape without providing an uneven portion for retaining the pushing member on the outer periphery of the fitting portion. it can. Therefore, no trace of compression is generated on the surface of the extruded member. That is, it is possible to obtain a weatherstrip having excellent appearance quality without any compression marks or connection steps on the outer surface constituting the design surface.

[Brief description of the drawings]

FIG. 1 is a cross-sectional perspective view of a weather strip according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view showing a main part of a molding die of the weather strip of FIG. 1;

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3;

FIG. 5 is a perspective view showing only a core mold of the molding die of FIG. 3;

FIG. 6 is a sectional view showing a conventional molding die.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Weather strip 12 ... Extrusion member 14 ... Molding part 16, 18, 20 ... Hollow part 30 ... Molding die 40 ... Core mold 42 ... Hollow molding part 52, 54, 56 ... Fitting part L ... Connection surface H ... interval

──────────────────────────────────────────────────の Continued on front page (51) Int.Cl. ⁷ Identification code FI B29K 105: 04 B29L 31:30

Claims (3)

(57) [Claims] 1. A weather strip forming die for forming a molded portion so as to be connected to an end of an extruded extruded member having a hollow portion, wherein a core forming the hollow portion of the molded portion is provided. The core mold has a rod-shaped hollow molded part, and a fitting part that projects in a rod shape from the end face of the hollow molded part and fits into the hollow part of the extruded member, and has an outer surface of the hollow molded part. A weather strip having a substantially constant width between the mold and the mold surface facing the mold, and an outer surface of the hollow molded portion protruding toward the mold surface from an outer surface of the fitting portion. Molding mold. 2. The extruding member is made of sponge rubber,
The molding die for a weather strip according to claim 1, wherein the molding part is made of solid rubber. 3. A weather strip obtained by molding a molded portion so as to be connected to an end of an extruded extruded member having a hollow portion, wherein the extruded member is made of sponge rubber, and the molded portion is made of sponge rubber. A weather strip made of solid rubber, wherein the molded portion is formed with a substantially constant width along the outer surface of the extruded member, and at least thinner than the extruded member, with a connection surface between them being interposed therebetween; .