JP6663699B2 - Method for manufacturing corded rubber sheet - Google Patents

Description

  The present invention relates to a method for producing a corded rubber sheet such as a chafer used for a pneumatic tire.

  The pneumatic tire shown in FIG. 9 is provided with a chafer 10 as a tire reinforcing material. The chafer 10 is formed of a cord-containing rubber sheet in which rubber is topped on both sides of a cord array in which a plurality of cords are arranged. As shown, the chafer 10 is arranged so as to sandwich the carcass ply 8, and the chaher 10 is bonded to a predetermined area of the carcass ply 8 at the time of forming a tire. In addition, during the bonding, if air is not sufficiently removed from between the two members, a process defect called air entry may occur.

  Patent Literature 1 discloses a method of forming an exhaust groove on the surface of a ply material including a plurality of cords arranged in a blind shape so as to promote removal of air without performing holeing. However, in such a method, it may be difficult to sufficiently remove the air, and a method capable of more reliably preventing air from entering is desired.

  Patent Literature 2 describes a holing device in which a needle body is pierced into an uncured tire ply to form a through hole for air release. However, in such a method of piercing the needle by piercing the needle, the needle may damage the cord included in the tire ply. In particular, when a plurality of cords are arranged in a mesh, it is difficult to pierce a needle while avoiding the cords.

JP 2013-230700 A JP 2003-154579 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for producing a corded rubber sheet that can prevent air from entering during tire molding.

  The above object can be achieved by the present invention as described below. That is, the method for manufacturing a corded rubber sheet according to the present invention, a plurality of cords are arranged in a mesh-like cord array body between a pair of calender rolls, the rubber roll on both sides of the cord array body by the calender roll. While topping, rubber topping is prevented at one or more locations in the width direction to form a through groove penetrating in the thickness direction.

  A through groove penetrating in the thickness direction is formed on the cord-containing rubber sheet manufactured by this method as described above. Therefore, at the time of tire molding, when attaching the corded rubber sheet to another member such as a carcass ply, air can be removed from between the two members through this through groove, thereby preventing air from entering. .

  The through-groove may be wide and open on one or both sides. In this case, for example, by directing the surface where the through groove widens and opens to another member such as a carcass ply to which the corded rubber sheet is bonded, the smooth removal of air is promoted, and the air entry is more effectively performed. Can be prevented.

  A projection may be provided on the outer peripheral surface of the calender roll, and the through groove may be formed by a pair of the projections facing each other at an interval corresponding to the thickness of the cord array. In this case, the through groove can be easily formed by a slight improvement of the calender roll.

  The calender roll may be divided in the width direction to provide a gap, and the through-groove may be formed by not rolling the rubber in the gap. In this case, the through groove can be easily formed by a slight improvement of the calender roll.

  A dam member may be provided upstream of the calender roll, and the penetration member may be locally damped by the dam member to form the through groove. In this case, the through groove can be easily formed by a slight improvement of the calender roll.

(A) Front view and (b) plan view schematically showing how a rubber sheet with a cord is manufactured. XX arrow sectional drawing of FIG. Sectional view showing how a through groove is formed by a pair of projections FIG. 4 is a plan view schematically showing a state in which a corded rubber sheet is manufactured in another embodiment. (A) A cross-sectional view of a through groove which is widened and opened on one side or (b) both sides. FIG. 4 is a plan view schematically showing a state in which a corded rubber sheet is manufactured in another embodiment. Sectional view showing how a through groove is formed by not pressing rubber in the gap (A) Front view and (b) Plan view schematically showing how to manufacture a corded rubber sheet in another embodiment. Sectional drawing which shows an example of the bead part of a pneumatic tire

  An embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows a cord arrangement 1 in which a plurality of cords C are arranged in a mesh shape between a pair of calender rolls 2, and rubber is applied to both sides of the cord arrangement 1 by the calender rolls 2. A state in which the sheet 5 is manufactured is schematically shown. An unvulcanized rubber bank 6 is arranged upstream of the calender roll 2, and the rubber supplied from the bank 6 is rolled and topped on the cord array 1. However, the rubber topping is not uniform, and this point will be described later.

  In the present embodiment, an example is shown in which the corded rubber sheet 5 is the raw material of the chafer 10 as the tire reinforcing material shown in FIG. The cord-containing rubber sheet 5 sent out from the calender roll 2 is cut by the cutter 11 into a plurality of strips having a small width.

  In FIG. 1, the cord array 1 and the cord-containing rubber sheet 5 are conveyed toward the right side, and therefore the left side in FIG. 1 is the upstream side. The width direction WD, the thickness direction TD, and the longitudinal direction LD are respectively the width direction, the thickness direction, and the longitudinal direction of the corded rubber sheet 5, but are also the width direction, the thickness direction, and the longitudinal direction of the cord array 1.

  The codes C of the code array 1 extend in a direction inclined with respect to the longitudinal direction LD, and a plurality of codes C are inclined in directions opposite to each other to form a mesh arrangement. As the cord C, organic fibers such as nylon, rayon, polyester, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), and aramid are preferably used, but not limited thereto.

  In the method of manufacturing the corded rubber sheet 5, while the rubber roll 2 is topped by the calender roll 2 on both sides of the cord array 1 as described above, the topping of the rubber is prevented at one or more locations in the width direction WD and the thickness is reduced. A through groove 3 penetrating through the TD is formed. In the present embodiment, as shown in FIG. 2, an example is shown in which two through grooves 3 are formed in a cord-containing rubber sheet 5 formed into a narrow band-like material. In the through groove 3, the cord C is exposed without the rubber being topped, through which air can pass in the thickness direction TD.

  When bonding the rubber sheet 5 with a cord to another member such as a carcass ply during tire molding, air is removed from between the two members through the through groove 3, thereby preventing air from entering. . As described above, in the method, a portion where the rubber is not topped (that is, the through groove 3) is intentionally formed in the corded rubber sheet 5, thereby preventing air from entering during tire molding. The molded unvulcanized tire is vulcanized, and the rubber flows into the through groove 3 by the rubber flow at that time.

  The width W3 of the through groove 3 is set to, for example, 1 mm or more, but is not particularly limited as long as air can pass. As described later, when the width dimension of the through groove 3 is not constant in the thickness direction TD, the width W3 indicates a minimum value. The thickness of the corded rubber sheet 5 is, for example, 0.95 to 1.5 mm.

  The position and the number of the through-grooves 3 formed in the cord-containing rubber sheet 5 are not particularly limited, but in the present embodiment, the through-grooves 3 are formed at two locations that become bent portions during tire molding. The bent portions correspond to the portions 10a and 10b of the chaher 10 bent in a U-shape in FIG. 9, and the through-grooves 3 are formed in these portions, so that the cord-containing rubber sheet 5 is easily bent, and Advantages such as generation of wrinkles in the chafer 10 can be obtained.

  In the example of FIG. 1, a projection 21 is provided on the outer peripheral surface of the calender roll 2, and the through groove 3 is formed by a pair of projections 21 facing each other at an interval corresponding to the thickness of the cord array 1. FIG. 3 shows how the pair of protrusions 21 form the through groove 3. The interval G between the outer peripheral surfaces of the pair of calender rolls 2 is set to a dimension corresponding to the thickness of the cord-containing rubber sheet 5, while the interval between the pair of projections 21 is a dimension corresponding to the thickness of the cord array 1. Is set with Therefore, rubber topping is prevented at the location where the protrusion 21 is set, and the through groove 3 is formed. According to this method, the through-groove 3 can be easily formed by making a slight improvement to the existing calender roll.

  The projections 21 are provided so as to extend in the circumferential direction of the calender roll 2. In the present embodiment, the pair of protrusions 21 extending annularly forms the streak-shaped through groove 3 continuously extending in the longitudinal direction LD. However, the present invention is not limited to this. For example, as shown in FIG. 4, the protrusion 21 may be interrupted at one or more locations in the circumferential direction of the calender roll 2. In this case, the through groove 3 extending intermittently in the longitudinal direction LD is formed, and the amount of rubber topped on the cord array 1 can be increased.

  As shown in FIG. 5, the through-groove 3 may be wide and open on one or both sides. In this case, for example, the surface in which the through groove 3 is widened and opened is directed to another member (for example, the carcass ply 8) to which the corded rubber sheet 5 is bonded, so that smooth removal of air is promoted. It can be more effectively prevented. Also, if the through groove 3 has an opening that does not widen on one side as shown in FIG. 5A, the amount of rubber to be topped can be increased as compared with the through groove 3 in FIG. 5B.

  As means for forming the through-grooves 3, other than those using the pair of protrusions 21 as described above can be adopted. For example, in another embodiment shown in FIG. 6, the calender roll 2 is divided in the width direction WD to provide the gap 22, and the through-groove 3 is formed by not rolling the rubber in the gap 22. Although not shown in FIG. 6, the lower calender roll 2 is provided with a gap 22 at the same position as the upper calender roll 2 as shown in FIG. Even when rubber enters the gap 22, the rubber is not rolled and is not topped by the cord array 1, so that the through groove 3 is formed.

  In the embodiment of FIG. 8, a blocking member 4 is provided upstream of the calender roll 2, and the penetration of rubber is locally blocked by the blocking member 4 to form the through groove 3. Since rubber does not enter between the pair of calender rolls 2 at the location where the damming member 4 is installed, the through groove 3 is formed at that portion. The damming member 4 can be used in combination with the above-described embodiment using the pair of protrusions 21 or the gap 22 between the calender rolls 2.

  In any of the above-described embodiments, an example in which the rubber is supplied between the pair of calender rolls 2 from the bank 6 of the unvulcanized rubber has been described. Alternatively, the unvulcanized rubber may be formed into a film. It is also possible to supply a rubber film consisting of: In this case, for example, a roll on which the rubber film has been wound may be arranged upstream of the calender roll 2 and the rubber film may be drawn out from the roll and supplied so as to reach both sides of the cord array 1.

  In the above-described embodiment, an example in which a cord-containing rubber sheet serving as a raw material of the chafer 10 which is a tire reinforcing material is manufactured is described. However, the present invention is not limited thereto. It is also possible to manufacture a corded rubber sheet as a member.

  The present invention is not limited to the above-described embodiment at all, and various improvements and modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Code arrangement body 2 Calender roll 3 Through groove 4 Damming member 5 Corded rubber sheet 6 Bank 21 Projection 22 Gap

Claims (4)

A plurality of cords arranged in a mesh form are passed through a pair of calender rolls, and rubber is topped on both sides of the cord arrangement by the calender rolls. To form a through groove penetrating in the thickness direction,
The provided with projections on the outer circumferential surface of the calender roll, the method for producing a coding array pair of Turkey over de-cored rubber sheet to form the through groove by the projection facing each other at a corresponding distance to the thickness of. A plurality of cords arranged in a mesh form are passed through a pair of calender rolls, and rubber is topped on both sides of the cord arrangement by the calender rolls. To form a through groove penetrating in the thickness direction,
Wherein by dividing the calender rolls in the width direction a gap, manufacturing method of Turkey over de-cored rubber sheet to form the through groove by not rolled rubber in the gap. A plurality of cords arranged in a mesh form are passed through a pair of calender rolls, and rubber is topped on both sides of the cord arrangement by the calender rolls. To form a through groove penetrating in the thickness direction,
The established the dam member on the upstream side of the calender roll method of blocking Turkey over de-cored rubber sheet to form the through groove stopped locally block the rubber penetration by members.   The method for producing a corded rubber sheet according to any one of claims 1 to 3, wherein the through groove is widened and opened on one or both sides.