JP2000351145A - Roller head rubber extrusion apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a thin sheet-like rubber product with high accuracy and high quality e.g. a rubber member for forming a tire whose crosssection is divided into a plurality of regions with a plurality of kinds of rubbers. SOLUTION: A rubber extrusion apparatus 3 with an extrusion head 5 for extruding a rubber extrusion body with a transversely long crosssection divided into a plurality of crosssectional region with a plurality of kinds of rubbers (q) extruded from a plurality of rubber extruder main bodies 2 and a roller head 4 arranged in the neighborhood of an extrusion hole 3A and consisting of upper and lower calender rolls 16U and 16L are provided. The height of opening of the extrusion hole 3A is made less than 3 times of the gap between the upper and lower calender rolls 16U and 16L.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is capable of molding a thin sheet-like rubber product such as a rubber member for forming a tire with high precision and high quality, in which a cross section is divided into a plurality of regions by a plurality of types of rubber. The present invention relates to a roller head rubber extruder.

[0002]

2. Description of the Related Art For example, in a tire, required characteristics in each part are different.
As illustrated in FIG. 10, inner liner rubber g1, chafer rubber g2, clinch rubber g3, sidewall rubber g4, breaker cushion g5, tread rubber g6.
For example, it is composed of a plurality of types of rubber members g having different compositions. In such a rubber member g, it is necessary to integrally form the clinch rubber g3 and the side wall rubber g4 and to form them in advance as one rubber product in order to improve a decrease in accuracy and an increase in the number of bonding steps accompanying the bonding. Have been done.

In recent years, it has been strongly desired to integrate the inner liner rubber g1 and the chafer rubber g2 as shown in FIGS. 11C and 11D for further improvement. FIG. 11D shows a case where the inner liner rubber is formed of two types of rubbers g1a and g1b.

[0004] On the other hand, a multi-extrusion apparatus using a plurality of rubber extruder bodies is generally used to form a rubber product divided into a plurality of cross-sectional areas y by a plurality of types of rubber. This multi-extrusion apparatus usually has a structure in which a plurality of rubber extruder bodies are provided side by side in an extrusion head, and the rubber from each rubber extruder body is aggregated into one in the extrusion head, and then the rubber is extruded from an extrusion port. It is formed into a predetermined sectional shape and discharged.

[0005] However, using the device of this structure,
As shown in FIGS. 11C and 11D, directly extruding a thin sheet-like rubber product having a width and a thickness t of 3.0 mm or less as a rubber extruded body is difficult because the rubber product is too thin. In addition, there is a problem that it is difficult to secure the manufacturing itself or its dimensional accuracy.

As a device for forming a thin sheet, there is known a roller head rubber extruder in which rubber extruded from a rubber extruder is rolled between a pair of calender rolls and thinly stretched.

Therefore, the present inventor has paid attention to this roller head rubber extruder, and has proposed that the rubber extruded body from the multiple extruder is further rolled by calender rolls.

[0008] However, when simply rolled with a calender roll, the sectional area y divided in the rubber extruded body is used.
Is deformed by being crushed. For example, as shown in FIGS. 11A and 11B, when each region y extends with a substantially constant thickness over the entire width of the rubber extruded body, this is notable. In particular, when the rubber extruded body is sectioned in the width direction by the cross-sectional area y0 as shown in FIGS. 11C and 11D, the distribution of the cross-sectional area y is largely distorted by the rolling, and furthermore, the area is further reduced. y
It has been found that the accuracy and quality of the product are greatly impaired, for example, distortion e occurs at the boundary of 0 as shown in FIG.

Therefore, the present invention provides a thin sheet-like rubber having a plurality of cross-sectional areas while maintaining the high precision and high quality of an extruded rubber extruded body without causing the adverse effects of rolling by the calender roll. An object of the present invention is to provide a roller head rubber extruder capable of stably forming a product.

[0010]

In order to achieve the above object, the invention of a roller head rubber extruding device according to claim 1 is provided.
A plurality of rubber extruder bodies, and an extrusion head for forming a rubber extruded body having a horizontally long cross section divided into a plurality of cross-sectional areas by a plurality of types of rubber discharged from the rubber extruder body and extruding from an extrusion port. A rubber extruding device having a roller head disposed near the extrusion port and comprising upper and lower calender rolls, and having an opening height H1 of the extrusion port, a gap between the upper and lower calender rolls. H2 is set to be 1.5 times or more and 3.25 times or less.

Further, in the invention of the roller head rubber extruding apparatus according to the present invention, the extruding head includes a preformer for temporarily dividing the plurality of types of rubber into a plurality of cross-sectional areas of the rubber extruded body on a head body. And a die plate for determining the cross-sectional shape of the rubber extruded body by molding the provisionally divided rubber.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, a roller head rubber extruder 1 includes a rubber extruder 3 having a plurality of rubber extruder bodies 2 and a roller head 4 arranged near an extrusion port 3A of the rubber extruder 3.

In this embodiment, the roller head rubber extruder 1 is provided with an inner liner rubber g1 as shown in FIG.
A case where a rubber product W0 for forming a tire, which is obtained by integrating a rubber g2 (hereinafter referred to as rubber g1) and a chafer rubber g2 (hereinafter referred to as rubber g2), is exemplified. This rubber product W0
Is a wide and thin sheet-like body having a thickness t0 of 3.0 mm or less and a shape factor of a ratio L0 / t0 of the width L0 to the thickness t0 of 200 or more. In this example, the thickness t0 is Is about 1.5 mm and the width L0 is about 500 mm (shape factor is 333).

FIG. 2 (B) shows a rubber extruded body W1 extruded by the rubber extruding device 3. The rubber extruded body W1 has a horizontally long cross section corresponding to a central cross section region y1 made of rubber g1. , And rubber g2. That is, the cross section of the rubber extruded body W1 is divided in the width direction without including a continuous area continuous from one end to the other end in the width direction. In other words, the cross section area y from the upper surface to the lower surface of the rubber extruded body W1 is It has a border line.

The rubber extruded body W1 is rolled by the roller head 4 to form a thin rubber product W0 in which the distribution of the cross-sectional areas y1 and y2 in the rubber extruded body W1 is maintained. In the drawing, the sectional area of the rubber product W0 corresponding to the sectional areas y1 and y2 is denoted by y.
1 'and y2'.

Next, in the present embodiment, the rubber extruder 3
Upper first rubber extruder body 2U for extruding rubber g2
And a lower second rubber extruder main body 2 for extruding the rubber g1.
L, each of the rubber extruder main bodies 2 having the extrusion ports 3A and
And an extrusion head 5 for fixing the front ends of the U and 2L.

The rubber extruder bodies 2U and 2L are
It has a well-known configuration in which rubbers g1 and g2 injected from each of the injection ports 31 are kneaded and melted by a screw shaft 32 driven by a motor M via a speed reducer.

The extrusion head 5 has a head body 6 for fixing the discharge ports 33 of the rubber extruder bodies 2U and 2L.
In addition, the preformer 9 and the die plate 19 are provided so as to be interchangeable via the base former 7.

Here, as shown in FIGS. 3 and 4, the preformer 9 has a horizontally long rectangular block shape.
Each rubber g1, g from the rubber extruder body 2U, 2L
A plurality (three in this example) of supply ports 11a, 11b, which are individually supplied via a rubber flow path 10 in the head body 6,
11b (hereinafter referred to as a supply port 11 when collectively referred to) and the rubbers g1 and g2 from the supply port 11
A merging channel 12 for merging into one rubber body G while temporarily dividing into 1 and y2, and a discharge port 1 in which the merging channel 12 opens
3 and so on.

In this embodiment, the preformer 9 is composed of a pair of upper and lower long shafts 9U and 9L abutting the mating surface 14, and connects the supply port 11 and the discharge port 13 to each mating surface 14A.
Is formed by notching. That is, the rubber g
One supply port 11a is formed in the lower long shaft 9L, and the supply port 11b for the rubber g2 is formed on both sides thereof and in the upper long shaft 9U. Each supply port 11 communicates with one of the flat and flat discharge ports 13 which opens horizontally by making the inclinations of the merging channels 12 different from each other, as schematically shown in FIG. 5.

The base former 7 has a block shape having a fitting concave portion 7A into which the preformer 9 is removably fitted, and faces the discharge port 13 so that the rubber body G from the discharge port 13 is formed. It has an inlet 15 for receiving the whole, and a guide passage 17 for guiding the rubber body G to the die plate 19. This guide channel 17 is shown in FIG.
As shown in (C), the cross-sectional shape is a parallel hole substantially equal to the discharge port 13 and the inflow port 15, thereby smoothing the rubber flow, and forming a boundary line between the provisionally divided cross-sectional areas. The degree of bonding between the rubbers g1 and g2 can be increased while maintaining stability.

The base former 7 has a die plate 19 detachably held at the tip thereof. In this embodiment, the die plate 19 can be pulled out of the base former 7 by being pulled in the width direction.

The die plate 19 has a molding channel 18 formed by extruding the rubber body G as the rubber extruded body W1 having a predetermined cross-sectional dimension and opening at the extrusion port 3A. The molding channel 18 is a parallel hole having a cross section substantially equal to that of the extrusion port 3A, and is electrically connected to the guide channel 17 via a step. The length L1 of the molding channel 18
Is preferably at least 2.0 times the opening height H1 of the extrusion port 3A, whereby the extruded rubber body W1 can be accurately formed into a predetermined cross-sectional dimension.

FIGS. 6A to 6D schematically show the state of the rubber at each of the sectional positions I, II, III, and IV in FIG.

Next, the roller head 4 is disposed in the vicinity of the extrusion port 3A.
U, 16L, for example, via a roll stand (not shown), and held in a lateral direction orthogonal to the rubber extrusion direction from the extrusion port 3A.
The lower calender rolls 16U and 16L are rotatably controlled at the same speed and synchronously with each other.

As described above, in the roller head rubber extruder 1, the rubber extruded body W1 once extruded and formed by the rubber extruder 3 is further rolled and stretched between the calender rolls 16U and 16L of the roller head 4. Therefore, a wide and thin sheet-like rubber product W0 having a thickness of 3.0 mm or less and a shape factor of 200 or more, which has been difficult by extrusion molding, can be formed with excellent thickness accuracy.

Here, in order to suppress a problem that the cross-sectional areas y1 and y2 of the rubber extruded body W1 are crushed and deformed by rolling and the distribution thereof is broken, the extrusion port 3A is used.
The opening height H1 of the calender rolls 16U, 16
It is necessary to set the gap H2 between L to 1.5 times or more and 3.25 times or less.

If the ratio H1 / H2 exceeds 3.25,
Distortion of the distribution of the cross-sectional areas y1 and y2 and distortion e
(Shown in FIG. 11E), and the accuracy and quality are greatly reduced. If the ratio H1 / H2 is less than 1.5, it is necessary to extrude the rubber extruded body W1 with a thickness of 4.5 mm or less to obtain a thin rubber product W0 with a thickness of 3.0 mm or less. Similarly, there is a possibility that accuracy and quality may be reduced.

In the roller head 4, the peripheral speed V2 of the calender rolls 16U and 16L is higher than the rubber extrusion speed V1 from the extrusion opening 3A, and in particular, the ratio V2 / V1 is changed to the ratio H1 / H2. 0.95-1.
It is preferably 15 times. Thereby, the extruded body W1
Is mainly extended in the rubber extrusion direction (length direction) without being substantially extended in the width direction, so that the distribution collapse of the cross-sectional area can be further suppressed. If it is less than 0.95 times, the spread in the width direction is too large, and the distribution is likely to break down. Conversely, if it exceeds 1.25 times, it is pulled too much in the length direction and the shape becomes unstable.

The cross-sectional shape of the rubber product W0 is generally such that the thickness t0 is constant in the width direction. A variety of profiles, for example, in the form of a single layer, can be formed. At this time, the outer peripheral surface of the calender roll is formed so as to match the profile, and the opening shape of the extrusion port 3A is also adjusted to the profile and the ratio H1 /
Set in consideration of the value of H2.

In the extrusion head 5, as shown in this example, between the extrusion port 3 A and the inflow port 13, without interposing the guide channel 17 and the molding channel 18 (die plate 19) on the downstream side. When the flow is conducted by the rubber flow path whose cross-sectional shape is flattened at a constant rate toward the extrusion port 3 in a state where the direction of the rubber flow is not sufficiently controlled.
A will be led. As a result, each rubber g
Steps tend to occur at the joints 1 and g2, and the rolling by the roller head 4 tends to cause the distribution of the cross-sectional area to collapse.

Next, as a rubber product W0, as shown in FIG.
The case where the inner liner rubber g1 is composed of different upper and lower rubbers g1a and g1b as shown in FIG.

At this time, the rubber extruder 3 extrudes each of the rubbers g1a, g1b, and g2 as shown in FIG.
Two rubber extruder bodies 2U, 2M and 2L are used.
The preformer 9 is, as schematically shown in FIG.
In this example, rubber g1a, rubber g1b, and g2 are individually supplied, and four supply ports 11a1, 11a2, 11b, and 11b are provided.
And rubber g1a, rubber g1b from this supply port 11,
It has a merging flow path 12 for merging into one rubber body G while temporarily dividing g2 into a sectional area y1a, y1b, y2, and a discharge port 13 through which the merging flow path 12 communicates.

As shown in FIG. 9, the discharge port 13 communicates with the extrusion port 3A via a guide flow path 17 and a forming flow path 18 in a die plate 19.

In the present application, the present invention can be used for forming rubber products for various uses without being limited to rubber products for forming tires. Also, the structure is not limited to those of two or three rubber extruders, and the preformer and the die plate can be changed to various structures.

[0036]

Since the present invention is configured as described above,
A thin sheet-like rubber product such as a rubber member for forming a tire, whose cross section is divided into a plurality of regions by a plurality of types of rubber, can be formed with high precision and high quality.

[Brief description of the drawings]

FIG. 1 is a side view of an apparatus according to an embodiment of the present invention.

FIG. 2A is a cross-sectional view of a final rubber product formed by the apparatus, and FIG. 2B is a cross-sectional view of a rubber extruded body which is an intermediate stage thereof.

FIG. 3 is a schematic diagram illustrating an extrusion head.

FIG. 4 is an exploded perspective view showing a preformer.

FIG. 5 is a perspective view schematically showing a supply port of a preformer.

6 (A) to 6 (D) show positions I, II, III,
FIG. 4 is a sectional view schematically showing a rubber state in IV.

FIG. 7 is a schematic diagram showing another embodiment of a rubber extrusion device.

FIG. 8 is a perspective view schematically showing a supply port of a preformer used therein.

FIG. 9 is an enlarged sectional view showing a preformer and a die plate.

FIG. 10 is a cross-sectional view illustrating a rubber member constituting the tire.

FIGS. 11A to 11E are cross-sectional views of a rubber product illustrating a conventional technique.

[Explanation of symbols]

 2, 2U, 2M, 2L Rubber extruder main body 3 Rubber extruder 3A Extrusion port 4 Roller head 5 Extrusion head 6 Head main body 9 Preformer 16U, 16L Calendar roll 19 Die plate y1, y1a, y1b, y2 Cross-sectional area W1 rubber extrusion body

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29L 7:00 30:00 F term (Reference) 4F207 AA45 AG01 AH20 AR12 KA01 KA17 KB21 KB28 KF14 KL63 KL67 KM15 KM16

Claims (2)

[Claims] 1. A plurality of rubber extruder bodies, and a rubber extruded body having a laterally long cross section divided into a plurality of cross-sectional areas by a plurality of types of rubber discharged from the rubber extruder main body, and pressed from an extrusion port. And a roller extruder having an extruding head and a roller head which is disposed near the extruding port and is composed of upper and lower calender rolls. A roller head rubber extruder wherein the gap H2 between calender rolls is 1.5 times or more and 3.25 times or less. 2. The extrusion head, comprising: a preformer for temporarily dividing the plurality of types of rubber into a plurality of cross-sectional areas of the rubber extruded body; 2. The roller head rubber extruding device according to claim 1, wherein a die plate for determining a cross-sectional shape of the rubber extruded body is freely replaceable.