JP6699326B2 - Calender roll and rubber strip manufacturing equipment - Google Patents

Description

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

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

  In order to improve the productivity, for example, in Patent Document 1 below, at least one of a pair of calender rolls facing each other is provided with a recessed portion to form a gap portion, and the gap portion is formed, and the gap portion has a sectional shape of a rubber strip. I have proposed 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.

JP, 2000-254980, A

  However, the calendar roll of Patent Document 1 has a large contact area between the recessed portion and the rubber strip, so 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 calender roll, which causes unevenness in width and thickness of the rubber strip. Further, in the calender roll of Patent Document 1, when the rotation speed of the calender roll is increased in order to further improve the productivity, the above-mentioned tackiness problem remarkably occurs, and the rubber strip may be cut. It was

  The present invention has been devised in view of the above situation, and the rolling surface of the first roll has a first curve that is recessed inward, and the rolling surface of the second roll projects outward. It is a main object to provide a calender roll and a rubber strip manufacturing apparatus capable of efficiently manufacturing a rubber strip excellent in uniformity based on having a curved line.

  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 a rolling surface of the first roll includes an axis of the first roll. The cross-sectional shape in a plane has a first curve that is recessed inward of the first roll with a first radius of curvature, and the rolling surface of the second roll faces the rolling surface of the first roll. And, the cross-sectional shape in a plane including the axis of the second roll has a second curve projecting outward of the second roll with a second radius of curvature, and the second radius of curvature is It is characterized in that it is larger than the first radius of curvature.

  In the calendar roll according to the present invention, the first curve and the second curve are meshed with each other to form a gap between the first roll and the second roll, and the gap is formed by the rubber strip. It is desirable to approximate the cross-sectional shape of

  In the calendar roll according to the present invention, the maximum diameter of the rolling surface of the second roll is preferably 103% or more of the minimum diameter of the rolling surface of the first roll.

  In the calendar roll according to the present invention, it is preferable that the minimum diameter of the rolling surface of the second roll is larger than the maximum diameter of the rolling surface of the first roll.

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

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

  In the rolling surface of the first roll of the present invention, the cross-sectional shape of a plane including the axis of the first roll has a first curve that is recessed inward of the first roll with a first radius of curvature, and The rolling surface of the roll is opposed to the rolling surface of the first roll, and the cross-sectional shape of a plane including the axial center of the second roll is a second curve protruding outward of the second roll with a second radius of curvature. have. In the calender roll including the first roll and the second roll, since the diameter of the rolling surface is different, the adhesiveness of the rubber strip can be controlled.

  In the present invention, the second radius of curvature is larger than the first radius of curvature. The second roll having such a second radius of curvature has a large radius of curvature, so that the rubber strip easily sticks to it, and when it protrudes outward, the rubber strip easily peels off. Therefore, the adhesive force of the rubber strip to the first roll and the second roll can be controlled to be substantially the same. Therefore, the calender roll can prevent the rubber strip from being unnecessarily adhered to any of the calender rolls, and can efficiently manufacture 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 sectional drawing of the calendar roll of this embodiment.

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 shows a conceptual diagram of a rubber strip manufacturing apparatus 1 of the present embodiment as a sectional view. As shown in FIG. 1, the rubber strip manufacturing apparatus 1 of the present embodiment includes a rubber extruder 2 that preforms and extrudes rubber G, and a rubber strip GS that is preformed and extruded from the rubber extruder 2 in the final shape. And a pair of calender rolls 3 to be roll-formed into the rubber strip GS. The rubber strip GS discharged from the calendar roll 3 is conveyed to the molding former 6 by the applicator 5 including the conveyor 4, for example, and is wound, whereby the rubber member for tire is manufactured.

  The rubber extruder 2 is, for example, a rubber extruder main body 7 that pushes in one direction while kneading the charged rubber G, and a gear pump 8 that is arranged downstream of the rubber extruder main body 7 and that 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 a screw shaft 7b is housed in a cylinder 7a. The screw shaft 7b is rotationally driven by, for example, an electric motor (not shown) to discharge the injected rubber G from the discharge port 7c of the cylinder 7a while kneading.

  The gear pump 8 is, for example, a constant volume extruder having a well-known structure in which a pair of extrusion gears 8b is provided in a casing 8a. The extrusion gear 8b is driven to rotate by, for example, an electric motor (not shown), and discharges 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 exchangeably connected to the downstream side of the gear pump 8 and a mouthpiece 9b that is detachably attached to the head body 9a and has a preforming port 9c opened. I have it. Therefore, the kneaded rubber G is molded into the preformed rubber strip GS by the extrusion head 9.

  The preforming port 9c of this embodiment is a relatively small opening having a horizontally long rectangle. Further, the rubber G can be extruded to the outside by being formed into a rectangular cross-sectional shape that is substantially the same as the preforming port 9c. The rubber extruder 2 having such a 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 first roll 10 and the second roll 11 are arranged such that their rotation axes 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 sectional view in a plane including the axis A1 of the first roll 10 and the axis A2 of the second roll 11 of the calender roll 3 of the present embodiment. As shown in FIG. 2, in the calender roll 3 of the present embodiment, for example, a first roll 10 and a second roll 11 having different cross-sectional shapes on a plane including the shaft cores A1 and A2 are arranged to face each other. ing.

  The first roll 10 preferably includes a rolling surface 12 that comes into contact with the rubber strip GS, and a pair of supporting surfaces 13 on both outer sides of the rolling surface 12 in the roll axial direction. The rolling surface 12 of the first roll 10 has, for example, a first curve 14 in which the cross-sectional shape in a plane including the axis A1 of the first roll 10 is recessed inward of the first roll 10 at a first radius of curvature R1, It has a pair of first straight lines 15 on both support surfaces 13 side of the first curve 14. The diameter of the rolling surface 12 of the first roll 10 is preferably the minimum diameter D1 at the central portion in the axial direction of the roll and the maximum diameter D2 at the portion connected to the support surface 13. The rolling surface 12 of the first roll 10 as described above can prevent the rubber strip GS from moving in the roll axial direction.

  The support surface 13 of the first roll 10 is preferably substantially cylindrical. The diameter of the support surface 13 of the first roll 10 is preferably substantially equal to the maximum diameter D2 of the rolling surface 12 of the first roll 10. The support surface 13 of the first roll 10 as described above can be easily processed, and the manufacturing cost of the first roll 10 can be reduced.

  The second roll 11 preferably includes a rolling surface 16 that comes into contact with the rubber strip GS, and a pair of support surfaces 17 on both outer sides of the rolling surface 16 in the roll axial direction. The rolling surface 16 of the second roll 11 has, for example, a second curve 18 whose cross-sectional shape in a plane including the axis A2 of the second roll 11 protrudes outward of the second roll 11 with a second radius of curvature R2. , And a pair of second straight lines 19 on both support surfaces 17 sides of the second curve 18. The diameter of the rolling surface 16 of the second roll 11 is preferably the maximum diameter D3 at the central portion in the roll axial direction and the minimum diameter D4 at the portion connected to the supporting surface 17. The rolling surface 16 of the second roll 11 suppresses the movement of the rubber strip GS in the roll axial direction, and the rubber strip GS is easily peeled off from both end sides in the roll axial direction, so that the rubber strip GS becomes unnecessary. It can suppress sticking.

  The support surface 17 of the second roll 11 is preferably substantially cylindrical. The diameter of the support surface 17 of the second roll 11 is preferably substantially equal to the minimum diameter D4 of the rolling surface 16 of the second roll 11. The supporting surface 17 of the second roll 11 as described above can be easily processed, and the manufacturing cost of the second roll 11 can be reduced.

  The rolling surface 16 of the second roll 11 is preferably opposed to the rolling surface 12 of the first roll 10. Further, the second curvature radius R2 of the second curve 18 of the rolling surface 16 of the second roll 11 is preferably larger than the first curvature radius R1 of the first curve 14 of the rolling surface 12 of the first roll 10.

  In the second roll 11 having such a second radius of curvature R2, the rubber strip GS easily adheres due to the large radius of curvature, and the rubber strip GS easily separates as it protrudes outward. .. On the other hand, in the first roll 10 having the first radius of curvature R1, the rubber strip GS is likely to be peeled off due to the small radius of curvature, and the rubber strip GS is easily adhered due to the inward depression. Therefore, the adhesive force of the rubber strip GS to the first roll 10 and the second roll 11 can be controlled to be substantially the same. Therefore, the calendar roll 3 can suppress the rubber strip GS from being unnecessarily adhered to the first roll 10 or the second roll 11, and efficiently manufacture the rubber strip GS having a uniform width and height. can do.

  The maximum diameter D3 of the rolling surface 16 of the second roll 11 is preferably 103% or more of the minimum diameter D1 of the rolling surface 12 of the first roll 10. The minimum diameter D4 of the rolling surface 16 of the second roll 11 is preferably larger than the maximum diameter D2 of the rolling surface 12 of the first roll 10. In the second roll 11 as described above, the rubber strip GS easily adheres due to the large diameter of the roll. Therefore, it becomes easier to control the adhesive force of the rubber strip GS to the first roll 10 and the adhesive force to the second roll 11.

  It is desirable that the first curve 14 of the first roll 10 and the second curve 18 of the second roll 11 mesh with each other to form a gap 20 between the first roll 10 and the second roll 11. The second straight line 19 of the rolling surface 16 of the second roll 11 is preferably substantially parallel to the first straight line 15 of the rolling surface 12 of the first roll 10. The second straight line 19 and the first straight line 15 can define the ends of the gap 20.

  The rubber strip GS is rolled between the first roll 10 and the second roll 11. Therefore, it is desirable that the gap portion 20 be close to the cross-sectional shape of the rubber strip GS. The calender roll 3 having such a gap 20 can form the rubber strip GS without requiring a knife cutting operation for width regulation.

  The surface temperature T2 of the rolling surface 16 of the second roll 11 is preferably lower than the surface temperature T1 of the rolling surface 12 of the first roll 10. This temperature difference (T1-T2) can be realized, for example, by heating the rolling surface 12 of the first roll 10. The temperature difference (T1-T2) is preferably 5 to 50°C. In such a second roll 11, the rubber strip GS is likely to adhere due to the low surface temperature T2. Therefore, it becomes easier to control the adhesive force of the rubber strip GS to the first roll 10 and the adhesive force to the second roll 11.

  Although a particularly preferred embodiment of the present invention has been described above in detail, the present invention is not limited to the illustrated embodiment and can be carried out by being modified into various aspects.

  For example, in the above-described embodiment, the rolling surface 16 of the second roll 11 has the second curve 18 and the second straight line 19, but the second straight line 19 may be omitted. In this case, the ends of the gap 20 may be defined by both ends of the second curve 18 and the first straight line 15 of the rolling surface 12 of the first roll 10.

  Rubber strips were manufactured using the rubber strip manufacturing apparatus shown in FIG. 1, and the occurrence rate of rubber strip troubles 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 tire uniformity performance was evaluated.

<Rubber strip trouble occurrence rate>
The number of troubles that had an influence on the production efficiency such as cutting of the rubber strip during the production of the rubber strip and adhesion to the roller was measured. The result is an index in which the trouble occurrence rate of Comparative Example 1 is 100, and the smaller the value is, the less the rubber strip trouble is.

<Tire uniformity performance>
Conicity was measured multiple times for each sample tire and their sum was determined. The result is an index in which the conicity of Comparative Example 1 is 100, and the smaller the value is, the better the tire uniformity is.

  The test results are shown in Tables 1 and 2.

  As is clear from Tables 1 and 2, it was confirmed that the rubber strips of Examples had a lower occurrence rate of troubles during production and were excellent in tire uniformity as compared with 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 higher than that of the conventional comparative example 1.

  The results of the tests are shown in Table 3.

  As is clear from Table 3, in the rubber strip manufacturing apparatus of the example, the trouble occurrence rate during manufacturing is low and the tire uniformity is excellent, even when the rotation speed of the calendar roll is high, as compared with the comparative example. Was confirmed.

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

Claims (6)

A calender roll for rolling a rubber strip extruded from a rubber extruder,
Including a first roll and a second roll,
The first roll and the second roll include a rolling surface in contact with the rubber strip, and cylindrical supporting surfaces on both outer sides in the roll axial direction of the rolling surface,
Wherein the rolling surface of the first roll, the cross-sectional shape of a plane including the axis of the first roll has a first curve which is recessed inwardly of said first roll at a first radius of curvature,
Wherein the rolling surface of the second roll is opposed to the rolling surface of the first roll, and the cross-sectional shape of a plane including the axis of the second roll, the second roll at a second radius of curvature It has a second curve that projects outwards,
The calender roll, wherein the second radius of curvature is larger than the first radius of curvature. The first curve and the second curve are meshed with each other to form a gap between the first roll and the second roll,
The calender roll according to claim 1, wherein the gap portion is similar to the cross-sectional shape of the rubber strip.   The calender roll according to claim 1 or 2, wherein the maximum diameter of the rolling surface of the second roll is 103% or more of the minimum diameter of the rolling surface of the first roll.   The calender roll according to any one of claims 1 to 3, wherein a minimum diameter of the rolling surface of the second roll is larger than a maximum diameter of the rolling surface of the first roll.   The calender roll according to claim 1, wherein a surface temperature of the rolled surface of the second roll is lower than a surface temperature of the rolled surface of the first roll. A rubber strip manufacturing apparatus,
A rubber strip manufacturing apparatus comprising the calender roll according to claim 1 and the rubber extruder.

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