JP6763192B2 - Calendar roll and rubber strip manufacturing equipment - Google Patents

Description

The present invention relates to a calendar roll and a rubber strip manufacturing apparatus capable of efficiently manufacturing a rubber strip having excellent uniformity.

Conventionally, a calendar roll for rolling a rubber strip that is preformed and extruded from a rubber extruder is known. Usually, in molding using a calendar roll, the thickness of the rubber strip is regulated by a pair of upper and lower calendar rolls, and the rubber strip formed by the calendar roll is regulated to a desired width by a knife cutting operation.

In order to improve productivity, for example, in Patent Document 1 below, a gap is formed by denting a recessed portion in at least one of a pair of opposing calendar rolls, and the gap is formed into a cross-sectional shape of a rubber strip. We are proposing a calendar roll that approximates to. In Patent Document 1 below, since the cross-sectional shape of the rubber strip is regulated by the recessed portion, the rubber strip is formed without requiring knife cutting work for width regulation.

Japanese Unexamined Patent Publication No. 2000-254980

However, since the calendar roll of Patent Document 1 has a large contact area between the recessed portion and the rubber strip, there is a problem that the rubber strip adheres to the recessed portion and is difficult to peel off. For this reason, the rubber strip may partially adhere to the calendar roll, causing the width and thickness of the rubber strip to become uneven. Further, in the calendar roll of Patent Document 1, when the rotation speed of the calendar roll is increased in order to further improve the productivity, the above-mentioned problem of adhesiveness may occur remarkably and the rubber strip may be cut. It was.

The inventors conducted an diligent development test and found that the adhesive strength of the rubber strip differs depending on the diameter of the calendar roll. Even in the calendar roll of Patent Document 1, the rolled surface of one of the calendar rolls has a small diameter due to the recessed portion. This causes a difference in the adhesive strength of the rubber strip to the calendar roll, but this difference in diameter, that is, the height of the recessed portion is set according to the thickness of the rubber strip, so that the rubber strip adheres. I couldn't control the force.

The present invention has been devised in view of the above circumstances, and is based on making the diameter of the support surface of the second roll larger than that of the support surface of the first roll, and provides a rubber strip having excellent uniformity. The main purpose is to provide a calendar roll and rubber strip manufacturing apparatus that can be manufactured efficiently.

The present invention is a calendar roll for rolling a rubber strip extruded from a rubber extruder, including a first roll and a second roll, and the first roll and the second roll are rolled in contact with the rubber strip. The rolled surface of the first roll includes a surface and a cylindrical support surface on both outer sides of the rolled surface in the roll axis direction, and the rolled surface of the first roll is a cylindrical small diameter portion having a diameter smaller than that of the support surface of the first roll. The rolled surface of the second roll is provided with a cylindrical equal-diameter portion facing the rolled surface of the first roll and having the same diameter as the support surface of the second roll. The support surface of the second roll is characterized in that the diameter is larger than that of the support surface of the first roll.

In the calendar roll according to the present invention, the small diameter portion and the equal diameter portion form a gap portion between the first roll and the second roll, and the gap portion has a cross-sectional shape of the rubber strip. It is desirable that they are similar.

In the calendar roll according to the present invention, it is desirable that the diameter of the support surface of the second roll is 103% or more of the diameter of the support surface of the first roll.

In the calendar roll according to the present invention, it is desirable that the surface temperature of the rolled surface of the second roll is lower than the surface temperature of the rolled surface of the first roll.

The present invention is a rubber strip manufacturing apparatus, and is characterized by including the calendar roll according to any one of the above and the rubber extruder.

The first roll and the second roll of the present invention include a rolled surface in contact with the rubber strip and a cylindrical support surface on both outer sides of the rolled surface in the roll axis direction, and the rolled surface of the first roll is the first roll. A cylindrical small diameter portion having a diameter smaller than that of the support surface of the second roll, and the rolled surface of the second roll faces the rolled surface of the first roll and has the same diameter as the support surface of the second roll. It has an equal diameter part. Since the width of the rubber strip is regulated in such a first roll, the rubber strip can be formed without requiring a knife cutting operation due to the width regulation. Further, since the above-mentioned second roll has a simple shape, it can be easily processed and the manufacturing cost can be reduced.

In the present invention, the support surface of the second roll has a larger diameter than the support surface of the first roll. Since the diameter of the equal diameter portion of such a second roll is also large, the adhesive force of the rubber strip can be increased. Therefore, the adhesive force of the rubber strip to the first roll and the second roll can be controlled substantially the same. Therefore, the calendar roll can prevent the rubber strip from being unnecessarily adhered to any of the calendar rolls, and can efficiently produce the rubber strip having a uniform width and height.

As described above, the calendar roll of the present invention can efficiently produce a rubber strip having excellent uniformity.

It is a conceptual diagram which shows one Embodiment of the rubber strip manufacturing apparatus of this invention. It is a front view of the calendar roll of this embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a conceptual view of the rubber strip manufacturing apparatus 1 of the present embodiment as a cross-sectional view. As shown in FIG. 1, the rubber strip manufacturing apparatus 1 of the present embodiment has a final shape of a rubber extruder 2 that premolds and extrudes rubber G and a rubber strip GS that is premolded and extruded from the rubber extruder 2. Includes a pair of calendar rolls 3 to be rolled into the rubber strip GS of. The rubber strip GS discharged from the calendar roll 3 is conveyed to the molding former 6 by an applicator 5 including a conveyor 4, and wound around the rubber strip GS to manufacture a rubber member for a tire.

The rubber extruder 2 is, for example, a rubber extruder main body 7 that pushes the charged rubber G in one direction while kneading it, and a gear pump 8 that is arranged downstream of the rubber extruder main body 7 and quantitatively pushes out the rubber G. And an extrusion head 9 for preforming the rubber G extruded from the gear pump 8.

The rubber extruder main body 7 has, for example, a well-known structure in which the screw shaft 7b is housed in the cylinder 7a. The screw shaft 7b is, for example, rotationally driven by an electric motor (not shown) to knead the charged rubber G and discharge it from the discharge port 7c of the cylinder 7a.

The gear pump 8 is, for example, a constant volume extruder having a well-known structure in which a pair of extrusion gears 8b are provided in a casing 8a. The extrusion gear 8b is, for example, rotationally driven by an electric motor (not shown) to discharge the kneaded rubber G from the casing 8a to the extrusion head 9.

The extrusion head 9 includes, for example, a block-shaped head body 9a that is interchangeably connected to the downstream side of the gear pump 8 and a mouthpiece 9b that is replaceably attached to the head body 9a and has a preformed opening 9c opened. I have. Therefore, the kneaded rubber G is formed into the preformed rubber strip GS by the extrusion head 9.

The preformed opening 9c of the present embodiment is a relatively small opening forming a horizontally long rectangle. Further, the rubber G can be molded into a rectangular cross-sectional shape substantially the same as the preforming port 9c and extruded to the outside. As such a rubber extruder 2, a rubber extruder 2 having a relatively small output is sufficient. However, the cross-sectional shape of the preformed rubber strip GS is not limited to the rectangular shape as described above.

The calendar roll 3 of the present embodiment includes, for example, a first roll 10 arranged on the upper side and a second roll 11 arranged on the lower side. The rotation axes of the first roll 10 and the second roll 11 are substantially parallel to each other. For example, the preformed rubber strip GS is formed into a final shape by being rotationally driven by an electric motor (not shown). It is molded into a rubber strip GS.

FIG. 2 shows a front view of the calendar roll 3 of the present embodiment. As shown in FIG. 2, in the calendar roll 3 of the present embodiment, for example, the first roll 10 and the second roll 11 having different shapes are arranged so as to face each other.

It is desirable that the first roll 10 includes a rolled surface 12 in contact with the rubber strip GS and a pair of cylindrical support surfaces 13 on both outer sides of the rolled surface 12 in the roll axial direction. The rolled surface 12 of the first roll 10 includes, for example, a cylindrical small-diameter portion 14 and a pair of tapered portions 15 on both outer sides of the small-diameter portion 14 in the roll axial direction. It is desirable that the diameter D1 of the small diameter portion 14 of the rolled surface 12 of the first roll 10 is smaller than the diameter D2 of the support surface 13 of the first roll 10. The height h of the step between the small diameter portion 14 of the first roll 10 and the support surface 13 is appropriately set according to, for example, the thickness of the rubber strip GS to be molded. Since the width of the rubber strip GS is regulated in such a first roll 10, the rubber strip GS can be formed without requiring a knife cutting operation due to the width regulation.

It is desirable that the second roll 11 includes a rolled surface 16 in contact with the rubber strip GS and a pair of cylindrical support surfaces 17 on both outer sides of the rolled surface 16 in the roll axial direction. The rolled surface 16 of the second roll 11 includes, for example, a cylindrical equal-diameter portion 18. It is desirable that the diameter D3 of the equal diameter portion 18 of the rolled surface 16 of the second roll 11 is the same as the diameter D3 of the support surface 17 of the second roll 11. Since such a second roll 11 has a simple shape, it can be easily processed and the manufacturing cost can be reduced.

It is desirable that the diameter D3 of the support surface 17 of the second roll 11 is larger than the diameter D2 of the support surface 13 of the first roll 10. In such a second roll 11, the rubber strip GS tends to adhere to the second roll 11 because the diameter D3 of the equal diameter portion 18 having the same diameter D3 as the support surface 17 is large. On the other hand, the rubber strip GS easily adheres to the first roll 10 as it is recessed inward by the small diameter portion 14 and the tapered portion 15. Therefore, the adhesive strength of the rubber strip GS to the first roll 10 and the second roll 11 can be controlled substantially the same. Therefore, the calendar roll 3 can prevent the rubber strip GS from being unnecessarily adhered to the first roll 10 or the second roll 11, and efficiently manufactures the rubber strip GS having a uniform width and height. can do.

The diameter D3 of the support surface 17 of the second roll 11 is preferably 103% or more of the diameter D2 of the support surface 13 of the first roll 10. When the diameter D3 of the support surface 17 of the second roll 11 is less than 103% of the diameter D2 of the support surface 13 of the first roll 10, the difference in diameter between the first roll 10 and the second roll 11 becomes small, and the rubber There is a possibility that the adhesive strength of the strip GS cannot be controlled.

It is desirable that the rolled surface 16 of the second roll 11 faces the rolled surface 12 of the first roll 10. Further, it is desirable that the small diameter portion 14 of the rolled surface 12 of the first roll 10 and the equal diameter portion 18 of the rolled surface 16 of the second roll 11 face each other substantially in parallel. Such a small diameter portion 14 of the first roll 10 and an equal diameter portion 18 of the second roll 11 can form a gap portion 19 between the first roll 10 and the second roll 11. The tapered portion 15 of the rolled surface 12 of the first roll 10 can define the end portion of the gap portion 19.

The rubber strip GS is rolled between the first roll 10 and the second roll 11. Therefore, it is desirable that the gap portion 19 approximates the cross-sectional shape of the rubber strip GS. The calendar roll 3 having such a gap 19 can form the rubber strip GS without requiring a knife cutting operation due to the width regulation.

It is desirable that the surface temperature T2 of the rolled surface 16 of the second roll 11 is lower than the surface temperature T1 of the rolled surface 12 of the first roll 10. This temperature difference (T1-T2) can be realized, for example, by heating the rolled surface 12 of the first roll 10. The temperature difference (T1-T2) is preferably 5 to 50 ° C. As the surface temperature T2 of such a second roll 11 is low, the rubber strip GS tends to adhere to the second roll 11. Therefore, the adhesive force of the rubber strip GS to the first roll 10 and the adhesive force to the second roll 11 can be further easily controlled.

Although the particularly preferable embodiment of the present invention has been described in detail above, the present invention is not limited to the illustrated embodiment and can be modified into various embodiments.

For example, in the above-described embodiment, the rolled surface 16 of the second roll 11 has an equal diameter portion 18, but the rolled surface 16 of the second roll 11 also has a small diameter portion like the first roll 10. You may. In this case, the adhesive force of the rubber strip GS can be controlled by the height of the step of each roll and the diameter of each roll.

Further, in the above-described embodiment, the small diameter portion 14 of the rolled surface 12 of the first roll 10 and the equal diameter portion 18 of the rolled surface 16 of the second roll 11 are both cylindrical, but for example, one of them is a drum. The other may have irregularities such as a barrel shape. Further, the rolled surface 12 of the first roll 10 and the rolled surface 16 of the second roll 11 may have tapered surfaces that taper in opposite directions.

A rubber strip was manufactured using the rubber strip manufacturing apparatus shown in FIG. 1, and the occurrence rate of rubber strip trouble during manufacturing was evaluated. Further, in order to evaluate the uniformity of the rubber strip, a pneumatic tire of size 235 / 45R18 using this rubber strip was prototyped, and the tire uniformity performance was evaluated.

<Rubber strip trouble occurrence rate>
The number of troubles that affected the manufacturing efficiency, such as cutting the rubber strip and sticking to the rollers during the manufacturing of the rubber strip, was measured. The result is an index with the trouble occurrence rate of Comparative Example 1 as 100, and the smaller the value, the less the rubber strip trouble.

<Tire uniformity performance>
For each test tire, the conicity was measured multiple times and the sum of them was calculated. The result is an index with the conicity of Comparative Example 1 as 100, and the smaller the value, the better the tire uniformity.

The test results are shown in Table 1.

As is clear from Table 1, it was confirmed that the rubber strips of the examples had a lower trouble occurrence rate during manufacturing and excellent tire uniformity as compared with the comparative examples.

Next, using the rubber strip manufacturing apparatus of the example, a confirmation test was conducted in which the rotation speed of the calendar roll was 1.5 times faster than that of the conventional comparative example 1.

The test results are shown in Table 2.

As is clear from Table 2, the rubber strip manufacturing apparatus of the example has a low occurrence rate of troubles during manufacturing and excellent tire uniformity even if the rotation speed of the calendar roll is increased as compared with the comparative example. Was confirmed.

2 Rubber extruder 3 Calendar roll 10 1st roll 11 2nd roll

Claims (4)

A calendar roll that rolls rubber strips extruded from a rubber extruder.
Including the first roll and the second roll
The first roll and the second roll include a rolled surface in contact with the rubber strip and a cylindrical support surface on both outer sides of the rolled surface in the roll axis direction.
The rolled surface of the first roll includes a cylindrical small diameter portion having a diameter smaller than that of the support surface of the first roll.
The rolled surface of the second roll is provided with a cylindrical equal-diameter portion facing the rolled surface of the first roll and having the same diameter as the support surface of the second roll.
A calendar roll characterized in that the diameter of the support surface of the second roll is 103% or more of the diameter of the support surface of the first roll. A calendar roll that rolls rubber strips extruded from a rubber extruder.
Including the first roll and the second roll
The first roll and the second roll include a rolled surface in contact with the rubber strip and a cylindrical support surface on both outer sides of the rolled surface in the roll axis direction.
The rolled surface of the first roll includes a cylindrical small diameter portion having a diameter smaller than that of the support surface of the first roll.
The rolled surface of the second roll is provided with a cylindrical equal-diameter portion facing the rolled surface of the first roll and having the same diameter as the support surface of the second roll.
The support surface of the second roll has a larger diameter than the support surface of the first roll.
A calendar roll characterized in that the surface temperature of the rolled surface of the second roll is lower than the surface temperature of the rolled surface of the first roll. The small diameter portion and the equal diameter portion form a gap portion between the first roll and the second roll.
The calendar roll according to claim 1 or 2 , wherein the gap is close to the cross-sectional shape of the rubber strip. It is a rubber strip manufacturing equipment
A rubber strip manufacturing apparatus comprising the calendar roll according to any one of claims 1 to 3 and the rubber extruder.

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