JP2017196838A - 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. The first roll 10 and the second roll 11 respectively include rolling faces 12, 16 abutting on the rubber strip GS and cylindrical support faces 13, 17 on both outer sides in a roll axial direction of the rolling faces 12, 16. The rolling face 12 of the first roll 10 includes a cylindrical small diameter part 14 with a diameter smaller than the support face 13 of the first roll 10. The rolling face 16 of the second roll 11 opposes the rolling face 12 of the first roll 10 and includes a cylindrical equal diameter part 18 with a same diameter as the support face 17 of the second roll 11. The support face 17 of the second roll 11 is larger in diameter than the support face 13 of the first roll 10.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 inventors have conducted extensive development tests and have 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 rolling surface of one calendar roll has a small diameter due to the recessed portion. This causes a difference in the adhesive strength of the rubber strip to the calender roll, but the difference in diameter, that is, the height of the dent, is set according to the thickness of the rubber strip. The force could not be controlled.

  The present invention has been devised in view of the actual situation as described above, and is based on the principle that the diameter of the support surface of the second roll is larger than the support surface of the first roll. The main object is to provide a calender roll and rubber strip manufacturing apparatus that can be manufactured efficiently.

  The present invention is a calender roll for rolling a rubber strip extruded from a rubber extruder, and includes a first roll and a second roll, and the first roll and the second roll are in contact with the rubber strip. And a cylindrical support surface on both outer sides in the roll axis direction of the rolling surface, and the rolling surface of the first roll has a cylindrical small diameter portion whose diameter is smaller than that of the support surface of the first roll. The rolling surface of the second roll is opposed to the rolling surface of the first roll, and has a cylindrical isometric portion 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.

  In the calendar roll according to the present invention, the small-diameter portion and the constant-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 to approximate.

  In the calender roll according to the present invention, it is preferable that a diameter of the support surface of the second roll is 103% or more of a diameter of the support 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 first roll and the second roll of the present invention include a rolling surface in contact with the rubber strip and a cylindrical support surface on both outer sides in the roll axis direction of the rolling surface, and the rolling surface of the first roll is the first roll. A cylindrical small-diameter portion whose diameter is smaller than that of the support surface, the rolling surface of the second roll is opposed to the rolling 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 for regulating the width. Moreover, since the above-mentioned 2nd roll has a simple shape, it is easy to process and can reduce manufacturing cost.

  In the present invention, the support surface of the second roll has a diameter larger than that of the support surface of the first roll. In such a second roll, the diameter of the equal-diameter portion is increased, so that the adhesive strength of the rubber strip can be increased. 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 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.
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 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, a first roll 10 and a second roll 11 having different shapes are arranged to face each other.

  The first roll 10 preferably includes a rolling surface 12 that contacts the rubber strip GS and a pair of cylindrical support surfaces 13 on both outer sides of the rolling surface 12 in the roll axis direction. The rolling 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 in the roll axis direction of the small-diameter portion 14. The diameter D1 of the small diameter portion 14 of the rolling surface 12 of the first roll 10 is desirably 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 the thickness of the rubber strip GS to be molded, for example. 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 for regulating the width.

  As for the 2nd roll 11, it is desirable to contain the rolling surface 16 which contacts the rubber strip GS, and a pair of cylindrical support surface 17 of the rolling axial direction both outer sides of the rolling surface 16. The rolling surface 16 of the 2nd roll 11 is provided with the cylindrical-shaped equal diameter part 18, for example. The diameter D3 of the equal diameter portion 18 of the rolling surface 16 of the second roll 11 is desirably the same as the diameter D3 of the support surface 17 of the second roll 11. Since the second roll 11 has a simple shape, it can be easily processed and the manufacturing cost can be reduced.

  The diameter D3 of the support surface 17 of the second roll 11 is desirably 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 easily adheres as the diameter D <b> 3 of the equal diameter portion 18 having the same diameter D <b> 3 as the support surface 17 is large. On the other hand, as the first roll 10 is recessed inward by the small diameter portion 14 and the tapered portion 15, the rubber strip GS is easily adhered. 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 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. If 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 is reduced, and the rubber There is a possibility that the adhesive strength of the strip GS cannot be controlled.

  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 small diameter portion 14 of the rolling surface 12 of the first roll 10 and the equal diameter portion 18 of the rolling 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 the 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 rolling 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. For this reason, 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 portion 19 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 includes the constant diameter portion 18, but the rolling surface 16 of the second roll 11 also includes a small diameter portion, like the first roll 10. May be. In this case, the adhesive strength of the rubber strip GS can be controlled by the height of the step of each roll and the diameter of each roll.

  In the above-described embodiment, the small diameter portion 14 of the rolling surface 12 of the first roll 10 and the equal diameter portion 18 of the rolling surface 16 of the second roll 11 are both cylindrical. You may have an unevenness | corrugation like the barrel shape on the other side. Moreover, the rolling surface 12 of the first roll 10 and the rolling 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 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 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 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 2.

  As is apparent from Table 2, the rubber strip manufacturing apparatus of the example has a low occurrence rate of trouble at the time of manufacture and excellent tire uniformity even when the rotation speed of the calendar roll is increased compared to the comparative example. Was confirmed.

2 Rubber Extruder 3 Calendar Roll 10 First Roll 11 Second Roll

Claims (5)

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 that contacts the rubber strip, and cylindrical support surfaces on both outer sides in the roll axis direction of the rolling surface,
The rolling 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 rolling surface of the second roll is provided with a cylindrical isometric portion facing the rolling surface of the first roll and having the same diameter as the support surface of the second roll,
The calender roll characterized in that the support surface of the second roll has a diameter larger than that of the support surface of the first roll. The small diameter portion and the equal diameter portion 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 diameter of the support surface of the second roll is 103% or more of a diameter of the support surface of the first roll.   The calender roll according to any one of claims 1 to 3, 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,
A rubber strip manufacturing apparatus comprising the calender roll according to claim 1 and the rubber extruder.

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