JP2010173617A - Tire and method of manufacturing tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire and a manufacturing method of the tire, capable of further restraining manufacturing failure caused when air enters between a green case and tread rubber. <P>SOLUTION: A pneumatic tire 1 has a tire skeleton part 14 including an annular ring-shaped carcass 12 locked on a pair of bead parts 10, and the tread rubber 16 arranged outside in the tire radial direction of the tire skeleton part 14, and has a peripheral directional cord 20 arranged inside in the tire radial direction more than the tread rubber 16. The peripheral directional cord 20 is wound in a plurality on the tire skeleton part 14 along the tire peripheral direction, and the peripheral directional cord 20 is spirally arranged over the other shoulder part 30 from at least one shoulder part 30. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a tire including a tire skeleton including an annular carcass locked to a pair of beads, and a tread rubber provided on the outer side in the tire radial direction of the tire skeleton, and a method for manufacturing the tire, The present invention relates to a tire and a tire manufacturing method that can suppress manufacturing defects caused by air entering between a green case and a tread rubber during the manufacture of the tire.

  2. Description of the Related Art Conventionally, in a manufacturing process of a tire mounted on an automobile or the like, a method of attaching a tread rubber constituting a tread to a green case made up of a carcass and a bead is widely used. In the manufacturing process of such a tire, there is a problem that air easily enters between the green case and the tread rubber when the tread rubber is attached to the green case.

  Therefore, a method is known in which a plurality of convex portions or a plurality of concave portions are formed on the surface of the tread rubber in contact with the green case in order to allow air that has entered between the green case and the tread rubber to escape. For example, Patent Document 1).

JP 2004-284165 A (page 3-4, Fig. 1-2)

  However, the conventional tire manufacturing method described above has the following problems. That is, even if a plurality of convex portions or a plurality of concave portions are formed on the tread rubber, there is a problem that the air that has entered between the green case and the tread rubber is not completely removed, resulting in manufacturing defects.

  Then, an object of this invention is to provide the tire and the manufacturing method of a tire which can further suppress the manufacture defect by air entering between a green case and a tread rubber.

  In order to solve the above-described problems, the present invention has the following features. First, the first feature of the present invention is that a tire skeleton portion (tire skeleton portion 14) including an annular carcass (carcass 12) locked to a pair of beads (bead portion 10), and a tire in the tire skeleton portion. A tire (pneumatic tire 1) provided with a tread rubber (tread rubber 16) provided on the radially outer side, and provided with a circumferential cord (circumferential cord 20) provided on the tire radial direction inner side than the tread rubber, The circumferential cord is wound around the tire frame portion a plurality of times along the tire circumferential direction (tire circumferential direction R), and the circumferential cord is spirally formed from at least one shoulder portion (shoulder portion 30) to the other shoulder portion. The gist is to be arranged.

  According to such a tire, the circumferential cord is provided on the inner side in the tire radial direction than the tread rubber, and is disposed in a spiral shape from one shoulder portion to the other shoulder portion. In addition, since the circumferential cord is wound around the tire skeleton part a plurality of times along the tire circumferential direction R, the air entering the tire skeleton part, that is, the green case and the tread rubber in the tire manufacturing process, Get out of the gap between the rubber and the circumferential cord.

  Accordingly, the tire can further suppress manufacturing defects due to air entering between the green case and the tread rubber.

  The second feature of the present invention relates to the first feature of the present invention, and is summarized in that the circumferential cord is constituted by a filament bundle in which a plurality of filaments (filaments 22) are twisted.

  The third feature of the present invention relates to the second feature of the present invention, and is summarized in that the circumferential cord is made of an organic fiber.

  A fourth feature of the present invention relates to any one of the first to third features of the present invention, and includes a side tread rubber (side tread rubber 17) provided on the outer side in the tread width direction of the tire frame portion, and the circumferential direction. The gist of the cord is that it is arranged from one tire side part (tire side part 32) located between one bead and one shoulder part to the other tire side part.

  A fifth feature of the present invention relates to any one of the first to fourth features of the present invention, comprising a belt layer (belt layer 18) wound around the outer periphery of the carcass, wherein the circumferential cord is formed from the belt layer. The gist is that it is also arranged on the outer side in the tire radial direction.

  A sixth feature of the present invention is that a tread rubber (tread) provided on the outer side in the tire radial direction of the green case is provided in a green case including an annular carcass (carcass 12) locked to a pair of beads (bead portion 10). A method of manufacturing a tire to be attached to rubber 16), in which a circumferential cord (circumferential cord 20) is spirally wound around a green case along a tire circumferential direction (tire circumferential direction R) (step S1); And a step (step S2) of attaching a tread rubber to the outer side in the tire radial direction from the green case around which the circumferential cord is wound, and the circumferential cord extends from at least one shoulder portion (shoulder portion 30) to the other shoulder. The gist is to be arranged over the part.

  According to the characteristics of the present invention, it is possible to provide a tire and a tire manufacturing method that can further suppress manufacturing defects caused by air entering between the green case and the tread rubber.

1 is a partially exploded perspective view including a cross section in a tread width direction of a pneumatic tire 1 according to an embodiment of the present invention. It is sectional drawing of the tread width direction of the pneumatic tire 1 which concerns on embodiment of this invention. 1 is a perspective view of a circumferential cord constituting a pneumatic tire 1 according to an embodiment of the present invention. It is a flowchart which shows the manufacturing method of the tire which concerns on embodiment of this invention.

  Next, embodiments of a tire and a tire manufacturing method according to the present invention will be described with reference to the drawings. Specifically, (1) overall configuration of tire, (2) tire manufacturing method, (3) comparative evaluation, (4) operation and effect, and (5) other embodiments will be described.

  In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions are different from actual ones.

  Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(1) Overall Configuration of Tire FIG. 1 is a partially exploded perspective view including a cross section in the tread width direction of a pneumatic tire 1 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view in the tread width direction of the pneumatic tire 1 according to the embodiment of the present invention. FIG. 3 is a perspective view of a circumferential cord constituting the pneumatic tire 1 according to the embodiment of the present invention.

  Each part which comprises the pneumatic tire 1 is demonstrated. Specifically, (1.1) bead part, (1.2) tire frame part, (1.3) tread rubber, (1.4) side tread rubber, (1.5) belt layer, and (1) .6) The circumferential direction code will be described.

(1.1) Bead part As shown in Drawings 1 and 2, pneumatic tire 1 has a pair of bead parts 10 containing at least bead core 10a and bead filler 10b. Specifically, a steel cord or the like is used for the bead core 10a constituting the bead unit 10.

(1.2) Tire Frame Part The pneumatic tire 1 includes a tire frame including an annular carcass 12 that is locked to a pair of bead parts 10 in a cross section in the width direction along the tire radial direction D and the tread width direction W. The unit 14 is provided. The tire skeleton portion 14 forms a skeleton of the pneumatic tire 1. The carcass 12 includes a carcass cord and a layer made of rubber that covers the carcass cord.

(1.3) Tread Rubber The pneumatic tire 1 includes a tread rubber 16 provided on the outer side in the tire radial direction of the tire frame portion 14. The tread rubber 16 is formed by sequentially stacking a plurality of rubber sheets on the tire frame portion 14.

(1.4) Side Tread Rubber The pneumatic tire 1 includes a side tread rubber 17 that is located on the tire side portion 32 and is provided on the outer side in the tread width direction of the tire frame portion 14. The side tread rubber 17 is formed by sequentially stacking a plurality of rubber sheets on the tire frame portion 14.

(1.5) Belt Layer The pneumatic tire 1 includes a belt layer 18 that reinforces the tread rubber 16 and is provided inside the tread rubber 16 in the tire radial direction. The belt layer 18 is wound around the outer periphery of the carcass 12. Specifically, the belt layer 18 includes a first belt layer 18a and a second belt layer 18b.

(1.6) Circumferential Cord The pneumatic tire 1 includes a circumferential cord 20 provided on the inner side in the tire radial direction from the tread rubber 16.

  The circumferential cord 20 is directly wound around the tire frame portion 14 a plurality of times along the tire circumferential direction R. More specifically, the circumferential cord 20 is disposed on the outer side in the tire radial direction than the belt layer 18, and is wound around the belt layer 18 and the tire frame portion 14 a plurality of times.

  The circumferential cord 20 is spirally disposed from at least one shoulder portion 30 to the other shoulder portion 30. In the present embodiment, the circumferential cord 20 is spirally disposed from one tire side portion 32 located between one bead portion 10 and one shoulder portion 30 to the other tire side portion 32. .

  The shoulder portion 30 is continuous from the end of the tread portion 28 that contacts the road surface, and corresponds to the shoulder portion of the pneumatic tire 1. The tire side portion 32 is connected to the shoulder portion 30 and includes the end portion 10e of the bead portion 10 and the tire maximum width portion 34.

  As shown in FIG. 3, the circumferential cord 20 is constituted by a filament bundle in which a plurality of filaments 22 are twisted without being covered with rubber. Specifically, the number of twists of the filament bundle is 35 times / 10 cm or more and 60 times / 10 cm or less. A gap is formed between each filament 22.

The circumferential cord 20 is composed of organic fibers. Specifically, the circumferential cord 20 is composed of an organic fiber cord made of polyethylene terephthalate, polyethylene naphthalate, polyamide synthetic fiber, or the like. The diameter D1 of the circumferential cord 20 is 0.2 mm or more and 1.0 mm or less.
(2) Tire Manufacturing Method Next, a tire manufacturing method according to this embodiment will be described with reference to FIG. FIG. 4 is a flowchart showing a tire manufacturing method according to this embodiment. The pneumatic tire 1 according to the present embodiment includes a green case (corresponding to a tire frame portion 14 after manufacture) including an annular carcass 12 that is locked to a pair of bead portions 10, and the outer side in the tire radial direction of the green case. It is manufactured by adhering to the tread rubber provided on.

  Specifically, the tire manufacturing method includes (2.1) a circumferential cord winding step and (2.2) a tread rubber attaching step.

(2.1) Circumferential cord winding step In the circumferential cord winding step of step S1, the circumferential cord 20 is wound around the green case a plurality of times along the tire circumferential direction R.

  The circumferential cord 20 is spirally disposed from at least one shoulder portion 30 to the other shoulder portion 30.

(2.2) Tread rubber attaching process In the tread rubber winding process of Step S2, the tread rubber 16 is attached to the outer side in the tire radial direction than the green case around which the circumferential cord 20 is wound.

  Further, in the tread rubber winding step in step S2, the side tread rubber 17 is attached to the outer side in the tread width direction than the green case around which the circumferential cord 20 is wound.

(3) Comparative Evaluation Next, in order to further clarify the effects of the present invention, comparative evaluation performed using pneumatic tires according to the following comparative examples and examples will be described. Specifically, (3.1) Evaluation method and (3.2) Evaluation result will be described. In addition, this invention is not limited at all by these examples.

(3.1) Evaluation method Air permeability was evaluated about the manufactured pneumatic tire by the method of the comparative example and the Example. The pneumatic tires according to comparative examples and examples used for comparative evaluation will be specifically described. The tire size condition for the pneumatic tire was 195 / 60R15.

  The pneumatic tire according to the example is the same as the pneumatic tire 1 of the embodiment. The pneumatic tire according to the comparative example is different from the pneumatic tire according to the embodiment in that the circumferential tire 20 is not provided.

(3.1.1) Air permeability evaluation Evaluation method: 100 pneumatic tires according to comparative examples and examples were prepared, and air permeability was evaluated for each by a shearography inspection. Specifically, in the shearography inspection, a photograph was taken from the inside of the tire, the presence or absence of air that entered between the green case and the tread rubber was determined using the photograph, and the air permeability was evaluated. The evaluation of air permeability was expressed as an index with the air permeability of the pneumatic tire according to the comparative example as 100. The smaller the index value, the less air that has entered between the green case and the tread rubber, and the better the air permeability.

  Moreover, about the pneumatic tire which concerns on a comparative example and an Example, the presence or absence of air was computed as an air generation rate.

(3.2) Evaluation Results Evaluation results using the pneumatic tires according to the comparative examples and examples described above will be described with reference to Table 1.

  The pneumatic tire according to the example was superior in air permeability and less air generation rate than the pneumatic tire according to the comparative example.

(4) Action / Effect According to the pneumatic tire 1 in the present embodiment, the circumferential cord 20 is provided on the inner side in the tire radial direction from the tread rubber 16 and spirals from one shoulder portion 30 to the other shoulder portion 30. Arranged in a shape. Further, since the circumferential cord 20 is wound around the tire skeleton 14 a plurality of times along the tire circumferential direction R, the circumferential cord 20 enters between the tire skeleton 14, that is, between the green case in the tire manufacturing process and the tread rubber 16. Air escapes from the gap between the tread rubber 16 and the circumferential cord 20.

  Therefore, the pneumatic tire 1 can further suppress manufacturing defects due to air entering between the green case and the tread rubber 16.

  According to the pneumatic tire 1 in the present embodiment, the circumferential cord 20 is configured by a filament bundle in which a plurality of filaments 22 are twisted, and therefore a gap is formed between the filaments 22. For this reason, in the tire manufacturing process, the circumferential cord 20 can absorb the air between the green case and the tread rubber 16 by the gap between the filaments 22. Therefore, the pneumatic tire 1 can further suppress manufacturing defects due to air entering between the green case and the tread rubber 16.

  Furthermore, the circumferential cord 20 is made of organic fibers. For this reason, in the tire manufacturing process, the circumferential cord 20 can further absorb the air between the green case and the tread rubber 16 by the gap between the organic fibers.

  According to the pneumatic tire 1 in the present embodiment, the circumferential cord 20 is disposed from one tire side portion 32 located between one bead and one shoulder portion 30 to the other tire side portion 32. The A space is formed in the tire side portion 32 when the carcass 12 is locked, and the end portion 10e of the bead portion 10 where air may remain between the green case and the side tread rubber 17 during vulcanization, The tire maximum width portion 34 is included.

  That is, since the circumferential cord 20 is also wound around the tire skeleton portion 14 located in the tire side portion 32 a plurality of times, it is possible to prevent air from entering between the green case and the side tread rubber 17.

According to the pneumatic tire 1 in the present embodiment, the circumferential cord 20 is disposed on the outer side in the tire radial direction with respect to the belt layer 18 and is wound around the belt layer 18 and the tire frame portion 14 in a spiral shape. For this reason, since the circumferential cord 20 is also spirally wound around the belt layer 18, air can be prevented from entering between the tire frame portion 14 and the tread rubber 16 including the belt layer 18.
(5) Other Embodiments As described above, the contents of the present invention have been disclosed through the embodiments of the present invention. However, it is understood that the description and drawings constituting a part of this disclosure limit the present invention. Should not. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, the embodiment of the present invention can be modified as follows.

  The circumferential cord 20 in the above-described embodiment is wound around the tire frame portion 14 a plurality of times along the tire circumferential direction R. Not limited to this, the circumferential cord 20 may be wound around the tire frame portion 14 a plurality of times along the tread width direction W. Also in this way, the pneumatic tire 1 can similarly suppress air from entering between the green case and the tread rubber 16.

  The circumferential cord 20 in the above-described embodiment is configured by a filament bundle in which a plurality of filaments 22 are twisted. However, the circumferential cord 20 may be formed by a cord that is not twisted, such as a metal wire.

  The circumferential cord 20 in the above-described embodiment is disposed on the outer side in the tire radial direction than the belt layer 18 and is wound around the belt layer 18 and the tire frame portion 14 in a spiral shape. The circumferential cord 20 is not limited to this, and may be disposed between the belt layer 18 and the tire frame portion 14 and may be wound only around the tire frame portion 14 in a spiral shape.

  The circumferential cord 20 in the above-described embodiment is disposed from one tire side portion 32 to the other tire side portion 32, but is not limited thereto, and is arranged from at least one shoulder portion 30 to the other shoulder portion 30. It only has to be installed.

  As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

D: tire radial direction, D1: diameter, R: tire circumferential direction, W: tread width direction, 1 ... pneumatic tire, 10 ... bead portion, 10a ... bead core, 10b ... bead filler, 10e ... end, 12 ... carcass 14 ... Tire frame, 16 ... tread rubber, 17 ... side tread rubber, 18 ... belt layer, 18a ... first belt layer, 18b ... second belt layer, 20 ... circumferential cord, 22 ... filament, 28 ... tread 30 ... Shoulder portion 32 ... Tire side portion 34 ... Tire maximum width portion

Claims (6)

A tire skeleton including an annular carcass locked to a pair of beads;
A tire provided with a tread rubber provided on the outer side of the tire frame in the tire radial direction,
A circumferential cord provided on the inner side in the tire radial direction than the tread rubber,
The circumferential cord is wound around the tire frame part a plurality of times along the tire circumferential direction,
The circumferential cord is a tire disposed in a spiral shape from at least one shoulder portion to the other shoulder portion.   The tire according to claim 1, wherein the circumferential cord is constituted by a filament bundle in which a plurality of filaments are twisted.   The tire according to claim 2, wherein the circumferential cord is made of an organic fiber. A side tread rubber provided on the outer side in the tread width direction of the tire frame portion,
The said circumferential direction code | cord | chord is arrange | positioned from one tire side part located between one said bead and one said shoulder part to the other tire side part. Tires. A belt layer wound around an outer peripheral portion of the carcass, wherein the circumferential cord is disposed on the outer side in the tire radial direction than the belt layer, and is wound spirally around the belt layer and the tire frame portion. 5. The tire according to any one of 4. A method of manufacturing a tire to be attached to a tread rubber provided on the outer side in the tire radial direction of the green case on a green case including an annular carcass locked to a pair of beads,
Winding the circumferential cord around the green case a plurality of times along the circumferential direction of the tire;
A step of attaching the tread rubber to the outer side in the tire radial direction than the green case around which the circumferential cord is wound;
The method of manufacturing a tire, wherein the circumferential cord is spirally disposed from at least one shoulder portion to the other shoulder portion.

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