JP2017196837A - Calender roll and rubber strip manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a calender roll and a rubber strip manufacturing apparatus capable of efficiently manufacturing a rubber strip excellent in homogeneity.SOLUTION: A calender roll 3 rolls a rubber strip GS extruded from a rubber extruder 2, and includes a first roll 10 and a second roll 11. A rolling face 12 of the first roll 10 has a first curve 14 depressing with a first curvature radius R1 inward the first roll 10 with regard to a cross-sectional shape in a plane including a shaft core A1 of the first roll 10. A rolling face 16 of the second roll 11 opposes the rolling face 12 of the first roll 10, and has a second curve 18 projecting with a second curvature radius R2 outward the second roll 11 with regard to a cross-sectional shape in a plane including a shaft core A2 of the second roll 11. The second curvature radius R2 is larger than the first curvature radius R1.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a calendar roll and a rubber strip manufacturing apparatus that can efficiently manufacture a rubber strip having excellent uniformity.

  2. Description of the Related Art 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 molded by the calendar roll is regulated to a desired width by a knife cutting operation.

  In order to improve productivity, for example, the following Patent Document 1 discloses that at least one of a pair of facing calender rolls is formed with a recessed portion by forming a recessed portion, and the clearance portion is formed in a cross-sectional shape of a rubber strip. A calendar roll that approximates to is proposed. 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 a knife cutting operation for width regulation.

JP 2000-254980 A

  However, the calendar roll of Patent Document 1 has a problem that the contact area between the recessed portion and the rubber strip is large, 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, causing the width and thickness of the rubber strip to be uneven. Further, in the calendar roll of Patent Document 1, if the rotation speed of the calendar roll is increased in order to further improve the productivity, the above-mentioned stickiness problem may occur remarkably and the rubber strip may be cut. It was.

  The present invention has been devised in view of the actual situation as described above, and has a first curve in which the rolling surface of the first roll is recessed inward, and the second rolling surface of the second roll protrudes outward. The main object is to provide a calender roll and a rubber strip manufacturing apparatus capable of efficiently manufacturing a rubber strip excellent in uniformity on the basis of having a curve.

  The present invention is a calendar roll for rolling a rubber strip extruded from a rubber extruder, and includes 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 protruding outward of the second roll with a second curvature radius, and the second curvature radius is 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 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.

  In the calendar roll according to the present invention, it is desirable that 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.

  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, it is preferable that the surface temperature of the rolling surface of the second roll is lower than the surface temperature of the rolling surface of the first roll.

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

  The rolling surface of the first roll of the present invention has a first curve in which a cross-sectional shape in a plane including the axis of the first roll is recessed toward the inside of the first roll with a first radius of curvature. The rolling surface of the roll is opposite to the rolling surface of the first roll, and the cross-sectional shape in a plane including the axis of the second roll protrudes outward from the second roll with a second radius of curvature. have. Since the calender roll including the first roll and the second roll has a difference in the diameter of the rolling surface, the adhesiveness of the rubber strip can be controlled.

  In the present invention, the second radius of curvature is greater than the first radius of curvature. The second roll having such a second radius of curvature tends to stick to the rubber strip as the radius of curvature increases, and the rubber strip tends to peel off as it protrudes outward. For this reason, the adhesive force of the rubber strip with respect to the first roll and the second roll can be controlled substantially the same. Therefore, the calender roll can suppress the rubber strip from being unnecessarily adhered to any of the calender rolls, and can efficiently produce a 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.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The conceptual diagram of the rubber strip manufacturing apparatus 1 of this embodiment is shown by FIG. 1 as sectional drawing. As shown in FIG. 1, the rubber strip manufacturing apparatus 1 according to the present embodiment has 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 a final shape. And a pair of calendar rolls 3 that are rolled into the rubber strip GS. The rubber strip GS discharged from the calender roll 3 is conveyed to the molding former 6 by an applicator 5 including a conveyor 4, for example, and a rubber member for tire is manufactured.

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

  The rubber extruder main body 7 has a known structure in which, for example, a screw shaft 7b is accommodated in a cylinder 7a. The screw shaft 7b is rotated by, for example, an electric motor (not shown), and discharges the charged 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 known structure in which a pair of extrusion gears 8b are provided in a casing 8a. The extrusion gear 8b is driven to rotate by, for example, an electric motor (not shown), thereby discharging the kneaded rubber G from the casing 8a to the extrusion head 9.

  The extrusion head 9 includes, for example, a block-shaped head main body 9a that is exchangeably connected to the downstream side of the gear pump 8, and a base 9b that is attached to the head main body 9a in a replaceable manner and that has a preforming port 9c opened. I have. Therefore, the kneaded rubber G is formed into a preformed rubber strip GS by the extrusion head 9.

  The preforming port 9c of this embodiment is a relatively small opening that forms a horizontally long rectangle. Further, the rubber G can be molded to have the same rectangular cross-sectional shape as the preforming port 9c and extruded to the outside. Such a rubber extruder 2 only needs to have a relatively small output. 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 disposed on the upper side and a second roll 11 disposed on the lower side. The first roll 10 and the second roll 11 are arranged so that their rotational axes are substantially parallel. For example, the first roll 10 and the second roll 11 are rotationally driven by an electric motor (not shown), so that the preformed rubber strip GS has a final shape. The rubber strip GS is molded.

  FIG. 2 shows a cross-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 calendar roll 3 of the present embodiment. As shown in FIG. 2, in the calendar roll 3 of the present embodiment, for example, a first roll 10 and a second roll 11 having different cross-sectional shapes in 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 contacts the rubber strip GS and a pair of support surfaces 13 on both outer sides in the roll axis direction of the rolling surface 12. The rolling surface 12 of the first roll 10 has, for example, a first curve 14 in which a cross-sectional shape in a plane including the axis A1 of the first roll 10 is recessed inward of the first roll 10 with a first curvature radius R1, and The first curve 14 has a pair of first straight lines 15 on both support surfaces 13 side. The diameter of the rolling surface 12 of the first roll 10 is preferably the minimum diameter D1 at the central portion in the roll axial direction and the maximum diameter D2 at the portion connected to the support surface 13. Such a rolling surface 12 of the first roll 10 can suppress the rubber strip GS from moving in the roll axis 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 desirably substantially equal to the maximum diameter D2 of the rolling surface 12 of the first roll 10. Such a support surface 13 of the first roll 10 can be easily processed, and the manufacturing cost of the first roll 10 can be reduced.

  As for the 2nd roll 11, it is desirable to include the rolling surface 16 which contacts the rubber strip GS, and a pair of support surface 17 of the rolling axial direction both outer side of the rolling surface 16. The rolling surface 16 of the second roll 11 has, for example, a second curve 18 in which a cross-sectional shape in a plane including the axis A2 of the second roll 11 protrudes outward from the second roll 11 with a second curvature radius R2. And a pair of second straight lines 19 on the both support surfaces 17 side 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 support surface 17. Such a rolling surface 16 of the second roll 11 suppresses the rubber strip GS from moving in the roll axis direction, and the rubber strip GS is easily peeled off from both ends in the roll axis direction, so that the rubber strip GS is 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. Such a support surface 17 of the second roll 11 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, it is desirable that the second curvature radius R2 of the second curve 18 of the rolling surface 16 of the second roll 11 is larger than the first curvature radius R1 of the first curve 14 of the rolling surface 12 of the first roll 10.

  The second roll 11 having the second radius of curvature R2 has a large radius of curvature, so that the rubber strip GS easily sticks, and the rubber strip GS easily peels off 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 easily peeled off as the radius of curvature is small, and the rubber strip GS is easily adhered as it is recessed inward. For this reason, the adhesive force of the rubber strip GS with respect to the 1st roll 10 and the 2nd roll 11 can be controlled 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 manufactures 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. In addition, the minimum diameter D4 of the rolling surface 16 of the second roll 11 is desirably larger than the maximum diameter D2 of the rolling surface 12 of the first roll 10. Such a 2nd roll 11 becomes easy to stick rubber strip GS with the diameter of a roll being large. For this reason, it becomes easier to control the adhesive strength of the rubber strip GS to the first roll 10 and the adhesive strength 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 are engaged to form a gap 20 between the first roll 10 and the second roll 11. It is desirable that the second straight line 19 of the rolling surface 16 of the second roll 11 is 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 end of the gap 20.

  The rubber strip GS is rolled between the first roll 10 and the second roll 11. For this reason, it is desirable that the gap 20 approximates the cross-sectional shape of the rubber strip GS. The calendar 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. Such a 2nd roll 11 becomes easy to stick rubber strip GS with surface temperature T2 being low. For this reason, 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.

  As mentioned above, although the especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.

  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 end 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.

  A rubber strip was manufactured using the rubber strip manufacturing apparatus shown in FIG. 1, and the occurrence rate of rubber strip troubles during the manufacturing was evaluated. In addition, 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 rate>
The number of troubles that had an effect on the production efficiency, such as cutting of the rubber strip and sticking to the roller during the production 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 rubber strip trouble.

<Tire uniformity performance>
For each sample tire, the conicity was measured multiple times and the total was determined. A result is an index | exponent which sets the connicity of the comparative example 1 to 100, and shows that tire uniformity is excellent, so that a numerical value is small.

  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 the examples had a lower trouble occurrence rate at the time of manufacture than the comparative examples, and excellent tire uniformity.

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

  The test results are shown in Table 3.

  As is clear from Table 3, the rubber strip manufacturing apparatus of the example has a lower occurrence rate of troubles and excellent tire uniformity even when the rotation speed of the calendar roll is higher than that of the comparative example. Was confirmed.

2 Rubber Extruder 3 Calendar Roll 10 First Roll 11 Second 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 rolling surface of the first roll has a first curve in which a cross-sectional shape in a plane including the axis of the first roll is recessed inward of the first roll with a first curvature radius,
The rolling surface of the second roll is opposed to 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 radius of curvature and is outside the second roll. Has a second curve protruding towards the
The calendar roll, wherein the second radius of curvature is larger than the first radius of curvature. The first curve and the second curve are meshed to form a gap between the first roll and the second roll,
The calender roll according to claim 1, wherein the gap portion approximates a cross-sectional shape of the rubber strip.   The calender roll according to claim 1 or 2, wherein a maximum diameter of the rolling surface of the second roll is 103% or more of a minimum diameter of the rolling surface of the first roll.   The calendar 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 any one of claims 1 to 4, wherein a surface temperature of the rolling surface of the second roll is lower than a surface temperature of the rolling surface of the first roll. A rubber strip manufacturing device,
6. A rubber strip manufacturing apparatus comprising the calendar roll according to claim 1 and the rubber extruder.

Images