JP6797364B2 - Extruder base - Google Patents

Description

The present invention relates to a mouthpiece for an extruder that extrudes a material rubber into a tire component having a predetermined cross-sectional shape.

In the raw tire manufacturing process, a sheet-shaped rubber member such as inner liner rubber, carcass ply, sidewall rubber, clinch rubber, or tread rubber is attached to a molding drum to form a cylindrical raw tire.

These sheet-shaped rubber members are extruded into a sheet shape with a predetermined cross-sectional shape by an extruder (see, for example, Patent Document 1).

The extruder is provided with an extruder base at the tip of the extruder body. In addition, a jig (preformer) immediately before the mouthpiece is usually provided adjacent to the upstream side of the mouthpiece for the extruder, and the material rubber sent by the screw is the rubber flow path formed in the preformer and for the extruder. It is formed into a predetermined shape by being discharged from a discharge port through a rubber flow path formed in a mouthpiece (see, for example, Patent Document 2).

When molding using the above-mentioned extruder, the material rubber does not easily flow to the edge portion of the rubber flow path of the extruder base, and when the discharged rubber sheet has an edge cut or is cut to a predetermined length. There is a problem of shrinking to. In order to solve such a problem, for example, an extruder base having a die plate 21 whose supply port side is processed as shown in FIGS. 7 and 8 is used. Note that FIG. 7 is an enlarged plan view of the conventional die plate viewed from below, and FIG. 8 is a plan view of the conventional die plate viewed from below.

The conventional die plate 21 is provided with a rubber reservoir 23 so that the material rubber can be taken in from the outside of the edge toward the edge portion 22 of the rubber flow path 24. By using the extruder base machine processed in this way, the discharge amount in the vicinity of the edge portion 22 is increased, so that the occurrence of edge breakage and shrinkage is suppressed.

JP-A-2002-160281 Japanese Unexamined Patent Publication No. 2012-81716

However, when the die plate as described above is used, although the occurrence of shrinkage can be eliminated, the material rubber flows inward from the outside in the width direction toward the edge at the edge portion 22, so that the material rubber is discharged at the edge portion 22. The increase in quantity is not sufficient. Therefore, there is a problem that the occurrence of edge breakage cannot be sufficiently suppressed.

Therefore, it is an object of the present invention to provide a mouthpiece for an extruder capable of sufficiently suppressing the occurrence of edge breakage of the extruded rubber member when the sheet-shaped rubber member is extruded.

The invention according to claim 1
A mouthpiece for an extruder that extrudes a tire component having a predetermined cross-sectional shape.
The supply port to which the material rubber is supplied and
A discharge port having the same cross-sectional shape as the above
It is provided with a rubber flow path leading from the supply port to the discharge port.
A rubber pool having a triangular inclined surface from the supply port side to the discharge port side is formed on both sides of the rubber flow path.
The inclined surfaces of the triangles are the apex closest to the supply port, the apex next to the supply port, and the apex located outside the width direction of the rubber flow path from the apex closest to the supply port, and the discharge port. The vertices closest to the above are three vertices, and the vertices are formed so as to taper from the supply port side toward the discharge port side, and further, starting from the vertex closest to the supply port, the discharge port is formed from the supply port side. It is a mouthpiece for an extruder characterized in that it is formed so as to be inclined toward the edge of the discharge port from the inside in the width direction of the rubber flow path toward the side .

The invention according to claim 2
The position of the apex closest to the discharge port on the inclined surface of the triangle substantially coincides with the position of the discharge port.
The extruder base according to claim 1, wherein the position of the apex closest to the supply port on the inclined surface of the triangle substantially coincides with the position of the supply port.

The invention according to claim 3
The mouthpiece for an extruder according to claim 1 or 2, wherein the width of the supply port of the rubber pool having the triangular inclined surface is 10 to 20 mm.

The invention according to claim 4
One of claims 1 to 3, wherein the vertical distance between the apex closest to the supply port and the apex next to the supply port on the inclined surface of the triangle is 10 to 15 mm. It is a mouthpiece for an extruder described in 1.

According to the present invention, it is possible to provide an extruder base that can sufficiently suppress the occurrence of edge breakage of the extruded rubber member when the sheet-shaped rubber member is extruded.

It is a front view of the supply port side of the mouthpiece for an extruder which concerns on one Embodiment of this invention. It is a top view of the die plate in one Embodiment of this invention seen from below. It is a perspective view which combined the mouthpiece for an extruder and the preformer which concerns on one Embodiment of this invention. It is a figure explaining the material rubber flow in the edge part of the mouthpiece for an extruder which concerns on one Embodiment of this invention. It is a YY arrow view of the mouthpiece for an extruder which concerns on one Embodiment of this invention. It is a front view which looked at the preformer from the discharge port side. It is an enlarged plan view which looked at the conventional die plate from below. It is a top view of the conventional die plate seen from below.

Hereinafter, the present invention will be described with reference to the drawings according to the embodiments.

1. 1. Extruder base FIG. 1 is a front view of the supply port side of the extruder base according to the present embodiment. In FIG. 1, the die plate 11 characteristic of the present invention is shown by a solid line, and the receiver 12 is shown by a chain double-dashed line. Further, FIG. 2 is a plan view of the die plate 11 as viewed from the X direction of FIG. 1, that is, from below. FIG. 3 is a perspective view in which the extruder base and the preformer according to the present embodiment are combined.

As shown in FIG. 1, the base 1 includes a die plate 11 and a receiving base 12. The base 1 is provided with a supply port 14 to which the material rubber is supplied, a discharge port 16 having the same shape as the tire component, and a rubber flow path 15 leading from the supply port 14 to the discharge port 16. Further, the rubber flow path 15 is formed with rubber pools having triangular inclined surfaces 13 from the supply port 14 toward the discharge port 16 on both sides.

The inclined surface 13 of each triangle is formed to taper from the supply port 14 side toward the discharge port 16, and further, with respect to the edge of the discharge port 16 from the supply port 14 side toward the discharge port 16. It is formed so as to be inclined outward.

As shown in FIG. 2, A is the apex of the triangular inclined surface 13 closest to the supply port 14, A'is the apex next to the supply port 14, and B is the apex closest to the discharge port 16. It is a close apex.

Further, C is the width at the supply port 14 of the rubber pool having the triangular inclined surface 13. D is the vertical distance between the apex B and the apex A'of the inclined surface 13 of the triangle, and is the height of the supply port.

FIG. 4 is a diagram for explaining the flow of the material rubber at the edge portion of the extruder base according to the present embodiment, and FIG. 5 is a YY arrow view of the extruder base according to the present embodiment. is there. In FIG. 5, 17 is a supply port forming end face, 18 is a discharge port forming end face, and t is the thickness of the base.

By providing the rubber pool having the triangular inclined surface 13 described above, as shown by the arrow in FIG. 4, when the material rubber moves from the supply port 14 to the discharge port 16, the material rubber on both sides of the rubber flow path 15 is provided. Can be forcibly flowed from the inside in the width direction toward the outside with respect to the edge of the discharge port 16. Further, as shown in FIG. 5, the material rubber flows downward from the apex A'to the apex B. As a result, the flow of the material rubber is concentrated on the edge of the rubber flow path 15 near the discharge port 16, and the occurrence of edge breakage of the extruded rubber member can be sufficiently suppressed.

2. 2. How to use the extruder base The above-mentioned base 1 is used in combination with the following preformers. That is, as shown in FIG. 3, the base 1 is attached to the discharge port side end surface of the preformer 3 on the downstream side of the preformer 3. The material rubber is supplied to the rubber flow path 15 of the base 1 through the preformer 3, and the tire constituent members having a predetermined cross-sectional shape are continuously discharged from the discharge port 16. The preformer 3 includes an upper die 31 and a lower die 32, and for example, as shown in FIG. 6, a discharge port 33 having a rectangular cross-sectional shape is formed.

3. 3. Preferable Embodiment of Extruder Mouthpiece The width C (FIG. 1) of the supply port 14 of the rubber reservoir having the triangular inclined surface 13 is preferably 10 to 20 mm.

When the width C is in this range, the effect of forming the triangular inclined surface 13 is more sufficiently exerted, so that the edge breakage is sufficiently suppressed.

Further, the vertical distance (height of the supply port) D between the apex B and the apex A'of the inclined surface 13 of the triangle is set to be equal to or higher than the height E (FIG. 6) of the discharge port 33 of the preformer 3, and the supply port is also set. When the width (frontage) of 14 is set to be equal to or larger than the width of the discharge port 33, the retention of the material rubber at the boundary between the base 1 and the preformer 3 is suppressed, and the material rubber flows more smoothly, which is preferable. Note that FIG. 6 is a front view of the preformer as viewed from the discharge port side.

Hereinafter, the present invention will be described in more detail based on Examples. In the following, the sidewall rubber of the tire of size 195 / 65R15 was continuously extruded for 20 m at an extrusion speed of 30.0 rpm. The height of the discharge port of the preformer (E in FIG. 6) was set to 10 mm.

1. 1. Extrusion molding of rubber member (1) Examples 1 to 15
Table 1 shows the width C of the rubber pool and the height D of the supply port on the triangular inclined surface 13 of the apex A, the apex A'and the apex B, which are processed into the shapes shown in FIGS. 1, 2 and 5. Extrusion processing was performed using the mouthpiece for the extruder changed as shown in.

(2) Comparative Example 1
Extrusion processing was performed using an extruder base whose shape on the supply port side is the same as that on the discharge port side.

(3) Comparative Example 2
Extrusion processing was performed using an extruder base having a rubber pool (width a: 5 mm, length b: 11 mm, distance c: 10 mm from the edge portion) shown in FIG. 7.

2. 2. Evaluation method The presence or absence of edge breakage was visually inspected, and evaluation was performed by a 5-point method based on the number of edge breakage cases. 4 points or more is particularly preferable. The evaluation results are summarized in Table 1.

From Table 1, in the case of Comparative Example 1 in which the shape on the supply port side was the same as the shape on the discharge port side and no measures were taken to increase the discharge amount in the vicinity of the edge portion, the evaluation point was 1 point. On the other hand, in Comparative Example 2 in which the mouthpiece provided with the rubber reservoir 23 shown in FIG. 7 was used, the evaluation points were improved to 2 points. However, even if the rubber reservoir 23 is provided, the number of points that are particularly preferable is not reached, and the effect of suppressing edge breakage cannot be said to be sufficient.

On the other hand, the triangle has the apex A of the inclined surface 13 of the triangle defined by the mouthpiece for the extruder of the present embodiment, and the thickness is reduced from the apex A toward the predetermined apex B where the thickness is the thinnest. In Examples 1 to 15 using the mouthpiece on which the inclined surface 13 of the above is formed, the evaluation points are equal to or higher than those of Comparative Example 2, and it can be seen that they are effective in suppressing edge breakage.

Further, even in the examples, when the width C of the rubber pool is 10 to 20 mm and the height D of the supply port is 10 to 15 mm (Examples 5, 6, 8, 9, 11, 12), the evaluation points are evaluated. Was 4 points or more, and it was found that a particularly remarkable effect was obtained.

Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments. It is possible to make various modifications to the above embodiments within the same and equivalent scope as the present invention.

1 Mouthpiece (Mouthpiece for extruder)
3 Preformer 11, 21 Die plate 12 Receiver 13 Triangular inclined surface 16, 33 Discharge port 14 Supply port 15, 24 Rubber flow path 17 Supply port forming end face 18 Discharge port forming end face 22 Edge part 23 Rubber pool 31 Upper mold 32 Lower mold A, A', B Apex a, C Width of rubber pool b Length of rubber pool c Distance from edge part D Supply port height E Discharge port height t Base thickness

Claims (4)

A mouthpiece for an extruder that extrudes a tire component having a predetermined cross-sectional shape.
The supply port to which the material rubber is supplied and
A discharge port having the same cross-sectional shape as the above
It is provided with a rubber flow path leading from the supply port to the discharge port.
A rubber pool having a triangular inclined surface from the supply port side to the discharge port side is formed on both sides of the rubber flow path.
The inclined surfaces of the triangles are the apex closest to the supply port, the apex next to the supply port, and the apex located outside the width direction of the rubber flow path from the apex closest to the supply port, and the discharge port. The vertices closest to the above are three vertices, and the vertices are formed so as to taper from the supply port side toward the discharge port side, and further, starting from the vertex closest to the supply port, the discharge port is formed from the supply port side. A mouthpiece for an extruder, which is formed so as to be inclined toward the edge of the discharge port from the inside in the width direction of the rubber flow path toward the side . The position of the apex closest to the discharge port on the inclined surface of the triangle substantially coincides with the position of the discharge port.
The mouthpiece for an extruder according to claim 1, wherein the position of the apex closest to the supply port on the inclined surface of the triangle substantially coincides with the position of the supply port. The mouthpiece for an extruder according to claim 1 or 2, wherein the width of the supply port of the rubber pool having the triangular inclined surface is 10 to 20 mm. One of claims 1 to 3, wherein the vertical distance between the apex closest to the supply port and the apex next to the supply port on the inclined surface of the triangle is 10 to 15 mm. The mouthpiece for the extruder described in.

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